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 3 of 14
May 22, 2026Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request body size limits on plugin HTTP endpoints CVE-2026-5308 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.9
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request body size limits on plugin HTTP endpoints which allows an attacker to cause a denial of service via crafted oversized HTTP requests.. Mattermost Advisory ID: MMSA-2026-00646
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 22, 2026Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers whichCVE-2026-4646 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to crash the plugin process via a crafted HTTP request to the PR details endpoint.. Mattermost Advisory ID: MMSA-2026-00638
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 22, 2026Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to archive the channel before removing persistent notificatioCVE-2026-4635 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to archive the channel before removing persistent notifications which allows authenticated user to crash the server via timing the creation of persistent notification message between the server deleting existing persistent notifications and archiving the channel.. Mattermost Advisory ID: MMSA-2026-00637
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 22, 2026Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users wCVE-2026-3636 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users without elevated permissions which allows a user without permissions to get data about team members roles via invoking various team API endpoints.. Mattermost Advisory ID: MMSA-2026-00626
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 22, 2026Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate file ownership and access control, which allows aCVE-2026-3473 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5.9
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate file ownership and access control, which allows an authenticated user to access and download files belonging to other users or teams via crafted Boards API requests using valid file IDs.. Mattermost Advisory ID: MMSA-2026-00620
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 21, 2026Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an mCVE-2026-4858 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 8
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL.. Mattermost Advisory ID: MMSA-2026-00640
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 21, 2026Mattermost Mobile Apps versions <=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allowsCVE-2026-22880 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.1
Mattermost Mobile Apps versions <=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 21, 2026Mattermost versions 11.5.x <= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an authCVE-2026-4055 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request. Mattermost Advisory ID: MMSA-2026-00629
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields in the Mattermost Calls plugin whichCVE-2026-6347 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 7.6
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields in the Mattermost Calls plugin which allows an attacker with access to a support packet to obtain TURN server credentials via the plaintext values present in the exported plugin configuration.. Mattermost Advisory ID: MMSA-2026-00605
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields before including them in support pacCVE-2026-6346 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 8.7
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields before including them in support packet generation, which allows a Mattermost System Admin or any party with access to a support packet to obtain sensitive credentials in plaintext via downloading a support packet from the System Console.. Mattermost Advisory ID: MMSA-2026-00607
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail prevent disclosure of created user password which allows a malicious attacker tCVE-2026-6345 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail prevent disclosure of created user password which allows a malicious attacker to impersonate a user via the use of some of those passwords.. Mattermost Advisory ID: MMSA-2026-00614
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check public/private permissions which allows members without these permissiCVE-2026-6343 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check public/private permissions which allows members without these permissions to access public playbooks via /get.. Mattermost Advisory ID: MMSA-2026-00591
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 11.4.x <= 11.4.3 fail to validate the X-Requested-With header on the burn-on-read reveal endpoint which allows an authentiCVE-2026-6339 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1, 11.4.x <= 11.4.3 fail to validate the X-Requested-With header on the burn-on-read reveal endpoint which allows an authenticated channel member to force the reveal of a burn-on-read message without recipient consent via a crafted Markdown image tag.. Mattermost Advisory ID: MMSA-2026-00636
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allowCVE-2026-6333 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.5
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost Advisory ID: MMSA-2026-00582
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to reCVE-2026-5163 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.5.x <= 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite endpoint.. Mattermost Advisory ID: MMSA-2026-00645
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent server-rendered content from closing an underlying application view in the Mattermost DesktCVE-2026-4643 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.5
Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent server-rendered content from closing an underlying application view in the Mattermost Desktop App which allows a malicious server or plugin to crash the desktop client via invoking {{window.close()}} in the renderer context, leading to a denial of service condition at the client level. Mattermost Advisory ID: MMSA-2026-00633
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to check if {{team_id}} was being changed when updating playbooks, allowing users with only {{ManCVE-2026-4286 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.1
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to check if {{team_id}} was being changed when updating playbooks, allowing users with only {{Manage Playbook Configurations}} permission to change a playbook's team, bypassing manage members restriction via PUT api. Mattermost Advisory ID: MMSA-2025-00552
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent an invalid URL from loading in a pop-up window in the Mattermost Desktop App which allows aCVE-2026-3471 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent an invalid URL from loading in a pop-up window in the Mattermost Desktop App which allows a malicious server owner to repeated crash the application via calling {{window.open('javascript:alert()');}}. Mattermost Advisory ID: MMSA-2026-00618
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to properly check for permissions when processing commands in the Gitlab plugin which allows noCVE-2026-3117 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to properly check for permissions when processing commands in the Gitlab plugin which allows normal users to uninstall instances or setup webhook connections via the {{gitlab instance {option}}} or the {{/gitlab webhook {option}}} commands. Mattermost Advisory ID: MMSA-2026-00600
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to enforce slash command trigger-word uniqueness during command updates which aCVE-2026-28732 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to enforce slash command trigger-word uniqueness during command updates which allows an authenticated team member with Manage Own Slash Commands permission to hijack and impersonate existing system or custom slash commands via editing their own slash command trigger to an already-registered trigger through the command update API. Mattermost Advisory ID: MMSA-2026-00597
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions tCVE-2026-6342 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via creating groups that share the same prefix as a whitelisted group. Mattermost Advisory ID: MMSA-2026-00601
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to have API-level checks on which groups the user can create issues or attach comments to whichCVE-2026-6341 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to have API-level checks on which groups the user can create issues or attach comments to which allows a user that is member of multiple groups to create issues to a locked group via direct API requests. Mattermost Advisory ID: MMSA-2026-00602
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate 7zip archive structure before processing which allows an authenticaCVE-2026-6340 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate 7zip archive structure before processing which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted 7zip file with excessive folder declarations.. Mattermost Advisory ID: MMSA-2026-00573
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to enforce client identity binding during the OAuth authorization code redemption flow which alloCVE-2026-6334 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.1
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to enforce client identity binding during the OAuth authorization code redemption flow which allows an authenticated OAuth client to redeem authorization codes issued to a different client via a crafted token exchange request.. Mattermost Advisory ID: MMSA-2026-00570
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster CVE-2026-4273 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.7
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a crafted invite confirmation with a RefreshedToken matching the original token. Mattermost Advisory ID: MMSA-2026-00575
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which aCVE-2026-3637 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to escape some variables that could contain malicious content during error page composition whichCVE-2026-3495 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.8
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to escape some variables that could contain malicious content during error page composition which allows an attacker with access to edit some site configuration to execute some malicious code via injecting some JS as part of those values.. Mattermost Advisory ID: MMSA-2026-00622
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to limit the size of the request body on the start meeting API endpoint, which CVE-2026-2325 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to limit the size of the request body on the start meeting API endpoint, which allows an authenticated attacker to cause resource exhaustion or denial of service via a crafted oversized HTTP POST request to {{/api/v1/meetings}}.. Mattermost Advisory ID: MMSA-2026-00608
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 18, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate that a remote cluster has access to a channel before processing memCVE-2026-28759 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel, including private channels, via crafted membership sync messages targeting channels the remote cluster is not authorized to access. Mattermost Advisory ID: MMSA-2026-00576
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 15, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to validate the response body of proxied images, which allows a remote attackerCVE-2026-4054 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to validate the response body of proxied images, which allows a remote attacker to enact client-side DoS via an SVG file served from an attacker-controlled origin under a non-SVG Content-Type header (e.g. image/png) embedded in an og:image meta tag or Markdown image link.. Mattermost Advisory ID: MMSA-2026-00630
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 15, 2026Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to enforce the PostEditTimeLimit on non-message post fields which allows an authenticated user toCVE-2026-4053 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.1
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to enforce the PostEditTimeLimit on non-message post fields which allows an authenticated user to modify post file attachments, props, and pin status after the edit window has expired via the post patch and update API endpoints.. Mattermost Advisory ID: MMSA-2026-00631
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 11, 2026OpenClaw before 2026.4.22 allows workspace dotenv files to override connector endpoint hosts for Matrix, Mattermost, IRC, and Synology connectors.CVE-2026-45003 · Other software · OpenClaw · reported by VulnCheckMedium 4.1
OpenClaw before 2026.4.22 allows workspace dotenv files to override connector endpoint hosts for Matrix, Mattermost, IRC, and Synology connectors. Attackers with workspace access can redirect runtime traffic to malicious endpoints by setting endpoint variables in dotenv files.
- Product
- OpenClaw
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 15, 2026Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link CVE-2026-3590 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 15, 2026Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to validate CSRF tokens on an authentication endpoint which aCVE-2026-28741 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.8
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to validate CSRF tokens on an authentication endpoint which allows an attacker to update a user's authentication method via a CSRF attack by tricking a user into visiting a malicious page. Mattermost Advisory ID: MMSA-2026-00625
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 15, 2026Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote sCVE-2026-27769 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 2.7
Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Mattermost Plugins versions <=2.1.3.0 fail to limit the request body size on the {{/changes}} webhook endpoint which allows an authenticated attacker to cause mCVE-2026-24661 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.7
Mattermost Plugins versions <=2.1.3.0 fail to limit the request body size on the {{/changes}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00611
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Mattermost Plugins versions <=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause mCVE-2026-21388 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 3.7
Mattermost Plugins versions <=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 6, 2026Mattermost Plugin Legal Hold versions <=1.1.4 fail to halt request processing after a failed authorization check in ServeHTTP which allows an authenticated attaCVE-2026-3524 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 8.8
Mattermost Plugin Legal Hold versions <=1.1.4 fail to halt request processing after a failed authorization check in ServeHTTP which allows an authenticated attacker to access, create, download, and delete legal hold data via crafted API requests to the plugin's endpoints. Mattermost Advisory ID: MMSA-2026-00621
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 3, 2026** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to validate file ownership when serving uploaded files.CVE-2026-28736 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to validate file ownership when serving uploaded files. This allows an authenticated attacker who knows a victim's fileID to read the content of the file. NOTE: Focalboard as a standalone product is not maintained and no fix will be issued.
- Product
- Focalboard
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 3, 2026** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to sanitize category IDs before incorporating them into dynamic SQL statements when reordering cateCVE-2026-25773 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 8.1
** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to sanitize category IDs before incorporating them into dynamic SQL statements when reordering categories. An attacker can inject a malicious SQL payload into the category id field, which is stored in the database and later executed unsanitized when the category reorder API processes the stored value. This Second-Order SQL Injection (Time-Based Blind) allows an authenticated attacker to exfiltrate sensitive data including password hashes of other users. NOTE: Focalboard as a standalone product is not maintained and no fix will be issued.
- Product
- Focalboard
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 26, 2026Mattermost Plugins versions <=11.4 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to validate incoming request size which allows an authenticated attacker to cause servicCVE-2026-3116 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.9
Mattermost Plugins versions <=11.4 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to validate incoming request size which allows an authenticated attacker to cause service disruption via the webhook endpoint. Mattermost Advisory ID: MMSA-2026-00589
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 26, 2026Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to apply view restrictions when retrieving group member IDs, CVE-2026-3115 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.3
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to apply view restrictions when retrieving group member IDs, which allows authenticated guest users to enumerate user IDs outside their allowed visibility scope via the group retrieval endpoint.. Mattermost Advisory ID: MMSA-2026-00594
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 26, 2026Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extrCVE-2026-3114 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.5
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 26, 2026Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to set permissions on downloaded bulk export which allows othCVE-2026-3113 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to set permissions on downloaded bulk export which allows other local users on the server to be able to read contents of the bulk export.. Mattermost Advisory ID: MMSA-2026-00593
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 26, 2026Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate Advanced Logging file target paths which allows sCVE-2026-3112 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 6.8
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate Advanced Logging file target paths which allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configuration in support packet generation. Mattermost Advisory ID: MMSA-2025-00562
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 26, 2026Mattermost Plugins versions <=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost vCVE-2026-3109 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comLow 2.2
Mattermost Plugins versions <=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 26, 2026Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to sanitize user-controlled post content in the mmctl commandCVE-2026-3108 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comHigh 8
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to sanitize user-controlled post content in the mmctl commands terminal output which allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences that enable screen manipulation, fake prompts, and clipboard hijacking.. Mattermost Advisory ID: MMSA-2026-00599
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 26, 2026Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to restrict team-level access when processing membership syncCVE-2026-4274 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5.4
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 25, 2026Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_controCVE-2026-27659 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 4.6
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578
- Product
- Mattermost
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 25, 2026Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to properly validate user identity in the OpenID {{IsSameUserCVE-2026-27656 · Other software · Mattermost · reported by responsibledisclosure@mattermost.comMedium 5.7
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to properly validate user identity in the OpenID {{IsSameUser()}} comparison logic, which allows an attacker to take over arbitrary user accounts via an overly permissive substring matching flaw in the user discovery flow.. Mattermost Advisory ID: MMSA-2026-00590
- 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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