Vulnerability database
Every flaw the U.S. government’s cybersecurity agency (CISA) has confirmed attackers are using, plus the new WordPress plugin and theme bugs published each day, sorted by what they mean for a small business. We refresh it twice a day. If you see something your website or office runs, tell us.
676 results · page 1 of 14
Oct 28, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component,CVE-2026-93851 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 8
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send an unintended API request, resulting in replacement of an installed plugin and code execution on the server, via a crafted post containing a forged mention reminder that the administrator clicks. Mattermost Advisory ID: MMSA-2026-00742
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 26, 2026Mattermost versions 11.7.x <= 11.7.10 fail to restrict which built-in roles can be assigned to a team member via the API, which allows a team admin to grant a tCVE-2026-93846 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.8
Mattermost versions 11.7.x <= 11.7.10 fail to restrict which built-in roles can be assigned to a team member via the API, which allows a team admin to grant a team member permissions beyond those permitted by the configured permission scheme via the {{update-team-member-roles}} REST API.. Mattermost Advisory ID: MMSA-2026-00734
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 26, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to bind the volume of text extracted from an uploaded PDF whiCVE-2026-93850 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to bind the volume of text extracted from an uploaded PDF which allows an authenticated user to exhaust server memory and cause a denial of service via a crafted PDF whose compressed content stream expands into a very large amount of text.. Mattermost Advisory ID: MMSA-2026-00769
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 26, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 Mattermost fail to apply allocation limits to the byte-string decoCVE-2026-93849 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 Mattermost fail to apply allocation limits to the byte-string decode paths in its WebSocket msgpack decoder, which allows an authenticated remote attacker to cause excessive server memory allocation via a crafted binary WebSocket frame declaring a Bin32 payload length of up to 4,294,967,295 bytes.. Mattermost Advisory ID: MMSA-2026-00768
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 26, 2026Mattermost versions 11.7.x <= 11.7.10 fail to apply outbound internal-connection filtering to the OpenID discovery endpoint request which allows a System AdminiCVE-2026-93848 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 2.7
Mattermost versions 11.7.x <= 11.7.10 fail to apply outbound internal-connection filtering to the OpenID discovery endpoint request which allows a System Administrator to determine whether internal addresses and ports are reachable from the server via an unauthenticated login request that triggers the discovery fetch.. Mattermost Advisory ID: MMSA-2026-00774
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 26, 2026Mattermost versions 11.7.x <= 11.7.10 fail to validate reserved system post types on the scheduled post creation and publication paths which allows an authenticCVE-2026-93847 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.5
Mattermost versions 11.7.x <= 11.7.10 fail to validate reserved system post types on the scheduled post creation and publication paths which allows an authenticated channel member to publish messages rendering as trusted system events via the scheduled post endpoint.. Mattermost Advisory ID: MMSA-2026-00732
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 26, 2026Mattermost versions <=11.9 11.1.9 11.5.8 11.10.7.0 fail to validate Zoom chat line length before slicing which allows an authenticated attacker to crash the AgeCVE-2026-116516 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions <=11.9 11.1.9 11.5.8 11.10.7.0 fail to validate Zoom chat line length before slicing which allows an authenticated attacker to crash the Agents plugin via summarizing a Zoom chat transcription containing short continuation lines. Mattermost Advisory ID: MMSA-2026-00723
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 22, 2026Mattermost versions 11.7.x <= 11.7.11 fail to validate null elements when decoding playbook import conditions which allows an authenticated attacker to crash thCVE-2026-13411 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.7.x <= 11.7.11 fail to validate null elements when decoding playbook import conditions which allows an authenticated attacker to crash the Playbooks plugin instance-wide via a crafted import request containing a null condition. Mattermost Advisory ID: MMSA-2026-00709
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to strip action integration secrets from post payloads before CVE-2026-19621 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to strip action integration secrets from post payloads before broadcasting post-deletion web socket events and returning thread API responses, which allows an authenticated channel member to obtain server-side webhook URLs and authentication context from interactive-message posts via the post_deleted websocket event or the threads REST API.. Mattermost Advisory ID: MMSA-2026-00766
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to sanitize authentication tokens before writing them to servCVE-2026-19600 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.5
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to sanitize authentication tokens before writing them to server log entries, which allows an attacker with access to server logs to obtain valid session tokens or OAuth access tokens and impersonate authenticated users via the debug-level Mattermost server log.. Mattermost Advisory ID: MMSA-2026-00763
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to reject OAuth application sessions in the account type switcCVE-2026-19076 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.4
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to reject OAuth application sessions in the account type switch endpoint, which allows an attacker with a valid OAuth bearer token for a target user to permanently take over that user's SSO-backed account by setting an attacker-controlled password and detaching the account from its identity provider via a crafted request to POST /api/v4/users/login/switch.. Mattermost Advisory ID: MMSA-2026-00758
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to restrict Slack import account binding to system administratCVE-2026-18799 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to restrict Slack import account binding to system administrator-initiated imports which allows an authenticated attacker with team admin privileges to force-add existing Mattermost users to their team and forge posts attributed to those users' identities via a crafted Slack export containing target users' email addresses.. Mattermost Advisory ID: MMSA-2026-00757
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate user’s permissions before other validations which CVE-2026-18560 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate user’s permissions before other validations which allows non-content reviewers to infer a post’s flagged status via direct API call.. Mattermost Advisory ID: MMSA-2026-00754
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search resCVE-2026-18256 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search results, which allows an authenticated user without permission to list private teams to disclose the ID, name, and display name of private teams via a modified team search request. Mattermost Advisory ID: MMSA-2026-00748
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate the invited recipient's email address when redeemiCVE-2026-18223 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate the invited recipient's email address when redeeming team and guest invitation tokens, which allows an authenticated attacker to join a team or gain unauthorized access to private channels via a forwarded or leaked invitation link.. Mattermost Advisory ID: MMSA-2026-00747
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to verify the integrity of the SAML RelayState POST parameter CVE-2026-16453 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 7.1
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to verify the integrity of the SAML RelayState POST parameter which allows an authenticated SAML user to join any team, including invite-only teams, via forging the team_id or invite_id fields in the RelayState.. Mattermost Advisory ID: MMSA-2026-00727
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to limit the size of remote image responses buffered in memoryCVE-2026-16251 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to limit the size of remote image responses buffered in memory during local image proxy direct fetches, which allows a remote attacker to cause memory exhaustion on the server via a crafted oversized image response.. Mattermost Advisory ID: MMSA-2026-00726
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to cap the number and size of mention keys stored in a user'sCVE-2026-19867 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.10.x <= 11.10.0, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to cap the number and size of mention keys stored in a user's notification properties, and to bound the quadratic multibyte-keyword matching performed for each post, which allows an authenticated user to degrade post-processing latency and consume excessive CPU on behalf of other members of any channel they share via storing an oversized notify_props.mention_keys list on their own profile.. Mattermost Advisory ID: MMSA-2026-00773
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to sanitize the active channel field returned by the user staCVE-2026-19603 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to sanitize the active channel field returned by the user status API endpoints, which allows an authenticated user to learn the channel ID of a private channel another user is actively viewing via the status endpoints, without being a member of that channel. Mattermost Advisory ID: MMSA-2026-00765
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to invalidate the stored AD/LDAP bind password when other conCVE-2026-19601 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.9
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to invalidate the stored AD/LDAP bind password when other connection settings (such as the server address) are changed, which allows a System Console administrator to disclose the plaintext bind password to an attacker-controlled server via the Test Connection / diagnostics feature. Mattermost Advisory ID: MMSA-2026-00764
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to require re-entry of the stored client secret when validatiCVE-2026-19541 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to require re-entry of the stored client secret when validating an outgoing OAuth connection, which allows an authenticated user with permission to manage outgoing OAuth connections to obtain the secret via pointing the token URL at an attacker-controlled endpoint and triggering validation.. Mattermost Advisory ID: MMSA-2026-00761
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to enforce DM/GM check on server side which allows an authentiCVE-2026-18795 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.4
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to enforce DM/GM check on server side which allows an authenticated user to quarantine a post belonging to DM or GM via direct API call.. Mattermost Advisory ID: MMSA-2026-00756
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 16, 2026Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate the combination of guest and admin scheme roles whCVE-2026-18551 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate the combination of guest and admin scheme roles which allows an authenticated attacker to escalate a guest account to team or channel admin via a crafted PUT request to the member roles API endpoint.. Mattermost Advisory ID: MMSA-2026-00752
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 22, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation oCVE-2026-96260 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 22, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint reqCVE-2026-96259 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5.5
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 22, 2026Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to limit the length of the post ID array accepted by the bulkCVE-2026-95666 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to limit the length of the post ID array accepted by the bulk reactions endpoint which allows an authenticated user to cause excessive database load via a crafted request to {{POST /api/v4/posts/ids/reactions}}.. Mattermost Advisory ID: MMSA-2026-00771
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 17, 2026Mattermost Desktop App versions <=6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which alloCVE-2026-75588 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 2.6
Mattermost Desktop App versions <=6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme. Mattermost Advisory ID: MMSA-2026-00717
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 17, 2026Mattermost Desktop App versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost serveCVE-2026-12284 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.7
Mattermost Desktop App versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server (or a user with script access to a connected server view) to disconnect an active call belonging to a different connected server via the desktopAPI.leaveCall IPC message. Mattermost Advisory ID: MMSA-2026-00699
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 16, 2026Mattermost Desktop App versions <=6.2 6.2.2.0 Fixed an issue where Mattermost Desktop did not sufficiently restrict server-rendered content from accessing localCVE-2026-75025 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.7
Mattermost Desktop App versions <=6.2 6.2.2.0 Fixed an issue where Mattermost Desktop did not sufficiently restrict server-rendered content from accessing local or private network resources. Thanks to game0v3r for contributing to this improvement under the Mattermost responsible disclosure policy. Mattermost Advisory ID: MMSA-2026-00698
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 Fail to sanitize Team objects returned by the data retention teamsCVE-2026-91181 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret invite_id and email, and use it to join the team without authorization, via GET /api/v4/data_retention/policies/{policy_id}/teams.. Mattermost Advisory ID: MMSA-2026-00702
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 Mattermost failed to validate Dynamic Client Registration redirect URIs by URL componenCVE-2026-12985 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.8
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 Mattermost failed to validate Dynamic Client Registration redirect URIs by URL component (matching glob patterns against the raw URI string instead) which allows a remote unauthenticated attacker to register an OAuth client with an attacker-controlled callback host that bypasses the configured redirect URI allowlist via a crafted redirect URI that places an allowlisted host/path suffix inside the query string.. Mattermost Advisory ID: MMSA-2026-00700
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.8, 10.11.x <= 10.11.22 fail to limit the nesting depth in the server-side Markdown parserCVE-2026-86349 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.8, 10.11.x <= 10.11.22 fail to limit the nesting depth in the server-side Markdown parser which allows an authenticated attacker to cause a denial of service (CPU resource exhaustion) via a crafted post containing deeply nested blockquotes or list items.. Mattermost Advisory ID: MMSA-2026-00707
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions <=11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 fail to recover from handler panics, which allows an authenticated user to crash the plugin via a posCVE-2026-86348 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions <=11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 fail to recover from handler panics, which allows an authenticated user to crash the plugin via a post-action request with an unexpected field type.. Mattermost Advisory ID: MMSA-2026-00701
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 fail to enforce authorization boundaries on the access control policy update endpoint wCVE-2026-82920 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5.5
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 fail to enforce authorization boundaries on the access control policy update endpoint which allows a channel or team administrator to detach a system-assigned ABAC parent policy via a crafted PUT /api/v4/access_control_policies request with an empty imports list.. Mattermost Advisory ID: MMSA-2026-00724
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate that a property field belongs to the specified ruCVE-2026-9812 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate that a property field belongs to the specified run before updating its value which allows an authenticated user with run property-management access to crash the Playbooks plugin via a REST request referencing a property field that belongs to a different run. Mattermost Advisory ID: MMSA-2026-00684
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel member-management permission during playbCVE-2026-8821 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 7.1
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel member-management permission during playbook run creation, allowing an authenticated channel member to add an arbitrary user to a restricted channel via the run owner field.. Mattermost Advisory ID: MMSA-2026-00677
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit size of unpacked SDP messages compressed with zlib, CVE-2026-5132 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit size of unpacked SDP messages compressed with zlib, which allows attacker to deny service or crash server via sending many SDP messages that unpack to large size.. Mattermost Advisory ID: MMSA-2026-00643
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding uploadeCVE-2026-15814 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding uploaded image files which allows an authenticated user to cause excessive server memory consumption and potential denial of service via uploading a specially crafted image as a profile picture, channel file attachment, team icon, or custom brand image. Mattermost Advisory ID: MMSA-2026-00719
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to enforce the board-creation permission which allows an unauCVE-2026-14344 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to enforce the board-creation permission which allows an unauthorized authenticated user to create boards via the board duplicate, boards-and-blocks, and archive-import endpoints.. Mattermost Advisory ID: MMSA-2026-00715
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to enforce board creation permissions when importing archive CVE-2026-14259 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to enforce board creation permissions when importing archive files which allows an authenticated non-guest team member to create Open or Private boards despite administrator restrictions via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00712
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate the type of `fields.properties` on block creationCVE-2026-13417 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate the type of `fields.properties` on block creation which allows an authenticated user with editor access to a board to crash the Boards plugin worker and trigger a denial of service via a child block whose `fields.properties` is a non-object value. Mattermost Advisory ID: MMSA-2026-00710
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to parse Markdown autolinks with unmatched trailing closing pCVE-2026-12882 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to parse Markdown autolinks with unmatched trailing closing parentheses in linear time, which allows an authenticated user with permission to create posts to cause excessive server CPU consumption and degrade availability for other users via specially crafted post or message attachment content. Mattermost Advisory ID: MMSA-2026-00703
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to properly enforce the limit of concurrent files being proceCVE-2026-11993 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to properly enforce the limit of concurrent files being processed and handled failed files, which allows a user with permission to upload files to spawn more goroutines than intended and block the indexing of other files via uploading heavy files constantly to the server.. Mattermost Advisory ID: MMSA-2026-00696
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate null entries in Microsoft Graph webhook notificatCVE-2026-10556 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5.3
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate null entries in Microsoft Graph webhook notification payloads, which allows an unauthenticated attacker to crash the Microsoft Calendar plugin process and deny calendar integration service to all users on the instance via a crafted {{POST}} request to the public webhook endpoint.. Mattermost Advisory ID: MMSA-2026-00693
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 14, 2026Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel action ownership which allows channel manCVE-2026-10542 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel action ownership which allows channel managers to update actions in other channels via the channel action update endpoint.. Mattermost Advisory ID: MMSA-2026-00692
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Aug 17, 2026Mattermost versions 10.11.x <= 10.11.20, 11.7.x <= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, whiCVE-2026-9693 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.5
Mattermost versions 10.11.x <= 10.11.20, 11.7.x <= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Aug 17, 2026Mattermost Desktop App versions <=6.2 6.2.2.0 fail to redact the pre-auth secret when generating a diagnostics report, which allows a local attacker with accessCVE-2026-75587 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.6
Mattermost Desktop App versions <=6.2 6.2.2.0 fail to redact the pre-auth secret when generating a diagnostics report, which allows a local attacker with access to a user's diagnostics report or log files to obtain the plaintext pre-auth secret configured for a connected server via inspecting the Server Connectivity (Step-3) diagnostics output. Mattermost Advisory ID: MMSA-2026-00716
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Aug 17, 2026Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to enforce PermissionManageBoardRoles on the channelId field of the batch endpoCVE-2026-9859 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to enforce PermissionManageBoardRoles on the channelId field of the batch endpoint, which allows an authenticated board editor to relink any board they can edit to an arbitrary channel via a crafted PATCH request. Mattermost Advisory ID: MMSA-2026-00686
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Aug 17, 2026Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to validate BoardMember.Scheme* fields server-side on insert and archive-importCVE-2026-9816 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 8.3
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to validate BoardMember.Scheme* fields server-side on insert and archive-import paths which allows a board editor or non-guest team member to grant board admin to arbitrary users via POST /api/v2/boards/{boardID}/members and POST /api/v2/teams/{teamID}/archive/import.. Mattermost Advisory ID: MMSA-2026-00685
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Aug 17, 2026Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fails to validate WebSocket command field types which allows an authenticated user tCVE-2026-10080 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fails to validate WebSocket command field types which allows an authenticated user to crash the plugin process and deny service to all Boards users via a custom_focalboard_SUBSCRIBE_TEAM message with a non-string teamId.. Mattermost Advisory ID: MMSA-2026-00687
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Where this comes from: the exploited list is CISA’s Known Exploited Vulnerabilities catalog. Everything else is the whole National Vulnerability Database, where each record is published by the team that found the bug (Wordfence, Patchstack, WPScan, the vendors themselves and others); we show who. Exploit odds are FIRST’s EPSS, updated daily. Titles and categories are ours, so check the linked record before acting on a detail. For a write-up of the big ones, see our advisories. Every vendor, and every WordPress plugin and theme with a recorded flaw, also has its own page. All of it is free to reuse as JSON, CSV or RSS.
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