Updated 10 h ago

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.

1,764exploited flaws on CISA’s list

35added in the last 30 days

456new WordPress flaws this week

390,714entries in the database

4,194 results · page 20 of 84

Jul 22, 2025Memory safety bugs present in Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140.CVE-2025-8040 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.8
Memory safety bugs present in Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025In some cases search terms persisted in the URL bar even after navigating away from the search page.CVE-2025-8039 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
In some cases search terms persisted in the URL bar even after navigating away from the search page. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025Thunderbird ignored paths when checking the validity of navigations in a frame.CVE-2025-8038 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.8
Thunderbird ignored paths when checking the validity of navigations in a frame. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025Setting a nameless cookie with an equals sign in the value shadowed other cookies.CVE-2025-8037 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.1
Setting a nameless cookie with an equals sign in the value shadowed other cookies. Even if the nameless cookie was set over HTTP and the shadowed cookie included the `Secure` attribute. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025Thunderbird cached CORS preflight responses across IP address changes.CVE-2025-8036 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
Thunderbird cached CORS preflight responses across IP address changes. This allowed circumventing CORS with DNS rebinding. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025Memory safety bugs present in Firefox ESR 128.12, Thunderbird ESR 128.12, Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140.CVE-2025-8035 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.8
Memory safety bugs present in Firefox ESR 128.12, Thunderbird ESR 128.12, Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025Memory safety bugs present in Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird ESR 128.12, Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and ThunderbCVE-2025-8034 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.8
Memory safety bugs present in Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird ESR 128.12, Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025The JavaScript engine did not handle closed generators correctly and it was possible to resume them leading to a nullptr deref.CVE-2025-8033 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.5
The JavaScript engine did not handle closed generators correctly and it was possible to resume them leading to a nullptr deref. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025XSLT document loading did not correctly propagate the source document which bypassed its CSP.CVE-2025-8032 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
XSLT document loading did not correctly propagate the source document which bypassed its CSP. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025The `username:password` part was not correctly stripped from URLs in CSP reports potentially leaking HTTP Basic Authentication credentials.CVE-2025-8031 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.8
The `username:password` part was not correctly stripped from URLs in CSP reports potentially leaking HTTP Basic Authentication credentials. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025Insufficient escaping in the “Copy as cURL” feature could potentially be used to trick a user into executing unexpected code.CVE-2025-8030 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
Insufficient escaping in the “Copy as cURL” feature could potentially be used to trick a user into executing unexpected code. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025Thunderbird executed `javascript:` URLs when used in `object` and `embed` tags.CVE-2025-8029 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
Thunderbird executed `javascript:` URLs when used in `object` and `embed` tags. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025On arm64, a WASM `br_table` instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrect computCVE-2025-8028 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.8
On arm64, a WASM `br_table` instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrect computation of the branch address. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jul 22, 2025On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack.CVE-2025-8027 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.5
On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 26, 2025Improper Input Validation vulnerability in Mozilla neqo leads to an unexploitable crash..This issue affects neqo: from 0.4.24 through 0.13.2.CVE-2025-6703 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgLow 2.3
Improper Input Validation vulnerability in Mozilla neqo leads to an unexploitable crash..This issue affects neqo: from 0.4.24 through 0.13.2.
Product
neqo
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com
Jun 24, 2025Memory safety bugs present in Firefox 139 and Thunderbird 139.CVE-2025-6436 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
Memory safety bugs present in Firefox 139 and Thunderbird 139. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025If a user saved a response from the Network tab in Devtools using the Save As context menu option, that file may not have been saved with the `.download` file eCVE-2025-6435 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
If a user saved a response from the Network tab in Devtools using the Save As context menu option, that file may not have been saved with the `.download` file extension. This could have led to the user inadvertently running a malicious executable. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org bugzilla.mozilla.org
Jun 24, 2025The exception page for the HTTPS-Only feature, displayed when a website is opened via HTTP, lacked an anti-clickjacking delay, potentially allowing an attacker CVE-2025-6434 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 4.3
The exception page for the HTTPS-Only feature, displayed when a website is opened via HTTP, lacked an anti-clickjacking delay, potentially allowing an attacker to trick a user into granting an exception and loading a webpage over HTTP. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025If a user visited a webpage with an invalid TLS certificate, and granted an exception, the webpage was able to provide a WebAuthn challenge that the user would CVE-2025-6433 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.8
If a user visited a webpage with an invalid TLS certificate, and granted an exception, the webpage was able to provide a WebAuthn challenge that the user would be prompted to complete. This is in violation of the WebAuthN spec which requires "a secure transport established without errors". This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025When Multi-Account Containers was enabled, DNS requests could have bypassed a SOCKS proxy when the domain name was invalid or the SOCKS proxy was not respondingCVE-2025-6432 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.6
When Multi-Account Containers was enabled, DNS requests could have bypassed a SOCKS proxy when the domain name was invalid or the SOCKS proxy was not responding. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025When a link can be opened in an external application, Firefox for Android will, by default, prompt the user before doing so.CVE-2025-6431 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.5
When a link can be opened in an external application, Firefox for Android will, by default, prompt the user before doing so. An attacker could have bypassed this prompt, potentially exposing the user to security vulnerabilities or privacy leaks in external applications. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 140.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `<embed>` or `<oCVE-2025-6430 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.1
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `<embed>` or `<object>` tag, potentially making a website vulnerable to a cross-site scripting attack. This vulnerability was fixed in Firefox 140, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag.CVE-2025-6429 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.5
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerability was fixed in Firefox 140, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025When a URL was provided in a link querystring parameter, Firefox for Android would follow that URL instead of the correct URL, potentially leading to phishing aCVE-2025-6428 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 4.3
When a URL was provided in a link querystring parameter, Firefox for Android would follow that URL instead of the correct URL, potentially leading to phishing attacks. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 140.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments.CVE-2025-6427 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.1
An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025The executable file warning did not warn users before opening files with the `terminal` extension.CVE-2025-6426 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.8
The executable file warning did not warn users before opening files with the `terminal` extension. *This bug only affects Firefox for macOS. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 140, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between contaCVE-2025-6425 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 4.3
An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles. This vulnerability was fixed in Firefox 140, Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 24, 2025A use-after-free in FontFaceSet resulted in a potentially exploitable crash.CVE-2025-6424 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.8
A use-after-free in FontFaceSet resulted in a potentially exploitable crash. This vulnerability was fixed in Firefox 140, Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 11, 2025A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without promptinCVE-2025-5986 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.5
A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without prompting, even if auto-saving is disabled. This behavior can be abused to fill the disk with garbage data (e.g. using /dev/urandom on Linux) or to leak Windows credentials via SMB links when the email is viewed in HTML mode. While user interaction is required to download the .pdf file, visual obfuscation can conceal the download trigger. Viewing the email in HTML mode is enough to load external content. This vulnerability was fixed in Thunderbird 128.11.1 and Thunderbird 139.0.2.
Product
Thunderbird
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 11, 2025A vulnerability in Mozilla VPN on macOS allows privilege escalation from a normal user to root.CVE-2025-5687 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 7.8
A vulnerability in Mozilla VPN on macOS allows privilege escalation from a normal user to root. *This bug only affects Mozilla VPN on macOS. Other operating systems are unaffected.*. This vulnerability was fixed in Mozilla VPN 2.28.0 (macOS).
Product
Mozilla VPN 2.28.0
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 11, 2025An integer overflow was present in `OrderedHashTable` used by the JavaScript engine.CVE-2025-49710 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.8
An integer overflow was present in `OrderedHashTable` used by the JavaScript engine. This vulnerability was fixed in Firefox 139.0.4.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Jun 11, 2025Certain canvas operations could have lead to memory corruption.CVE-2025-49709 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.8
Certain canvas operations could have lead to memory corruption. This vulnerability was fixed in Firefox 139.0.4.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025Memory safety bugs present in Firefox 138 and Thunderbird 138.CVE-2025-5272 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 7.3
Memory safety bugs present in Firefox 138 and Thunderbird 138. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 139 and Thunderbird 139.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025Previewing a response in Devtools ignored CSP headers, which could have allowed content injection attacks.CVE-2025-5271 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.5
Previewing a response in Devtools ignored CSP headers, which could have allowed content injection attacks. This vulnerability was fixed in Firefox 139 and Thunderbird 139.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled.CVE-2025-5270 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 7.5
In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vulnerability was fixed in Firefox 139 and Thunderbird 139.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10.CVE-2025-5269 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox ESR 128.11 and Thunderbird 128.11.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10.CVE-2025-5268 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025A clickjacking vulnerability could have been used to trick a user into leaking saved payment card details to a malicious page.CVE-2025-5267 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 5.4
A clickjacking vulnerability could have been used to trick a user into leaking saved payment card details to a malicious page. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks.CVE-2025-5266 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 4.3
Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025Due to insufficient escaping of the ampersand character in the “Copy as cURL” feature, an attacker could trick a user into using this command, potentially leadiCVE-2025-5265 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 4.8
Due to insufficient escaping of the ampersand character in the “Copy as cURL” feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. *This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025Due to insufficient escaping of the newline character in the “Copy as cURL” feature, an attacker could trick a user into using this command, potentially leadingCVE-2025-5264 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 4.8
Due to insufficient escaping of the newline character in the “Copy as cURL” feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025Error handling for script execution was incorrectly isolated from web content, which could have allowed cross-origin leak attacks.CVE-2025-5263 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 4.3
Error handling for script execution was incorrectly isolated from web content, which could have allowed cross-origin leak attacks. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 27, 2025A double-free could have occurred in `vpx_codec_enc_init_multi` after a failed allocation when initializing the encoder for WebRTC.CVE-2025-5262 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 7.5
A double-free could have occurred in `vpx_codec_enc_init_multi` after a failed allocation when initializing the encoder for WebRTC. This could have caused memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 139 and Thunderbird < 128.11.
Product
Thunderbird
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 21, 2025Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilized non-HTTPCVE-2025-5020 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 4.3
Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilized non-HTTP schemes used internally by the Firefox iOS client. This vulnerability was fixed in Firefox for iOS 139.
Product
Firefox for iOS
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 17, 2025An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes.CVE-2025-4919 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.8
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 17, 2025An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object.CVE-2025-4918 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgCritical 9.8
An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.
Product
Firefox
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 14, 2025It was possible to craft an email that showed a tracking link as an attachment.CVE-2025-3932 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.5
It was possible to craft an email that showed a tracking link as an attachment. If the user attempted to open the attachment, Thunderbird automatically accessed the link. The configuration to block remote content did not prevent that. Thunderbird has been fixed to no longer allow access to web pages listed in the X-Mozilla-External-Attachment-URL header of an email. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.
Product
Thunderbird
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 14, 2025Thunderbird's handling of the X-Mozilla-External-Attachment-URL header can be exploited to execute JavaScript in the file:/// context.CVE-2025-3909 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 8.1
Thunderbird's handling of the X-Mozilla-External-Attachment-URL header can be exploited to execute JavaScript in the file:/// context. By crafting a nested email attachment (message/rfc822) and setting its content type to application/pdf, Thunderbird may incorrectly render it as HTML when opened, allowing the embedded JavaScript to run without requiring a file download. This behavior relies on Thunderbird auto-saving the attachment to /tmp and linking to it via the file:/// protocol, potentially enabling JavaScript execution as part of the HTML. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.
Product
Thunderbird
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
May 14, 2025Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used.CVE-2025-3875 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgHigh 7.5
Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an (invalid) value "Spoofed Name ", Thunderbird treats spoofed@example.com as the actual address. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.
Product
Thunderbird
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org
Apr 30, 2025Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into tCVE-2025-3859 · Computers, phones & browsers · Mozilla · reported by security@mozilla.orgMedium 6.1
Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage. This vulnerability was fixed in Focus 138.
Product
Focus
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record bugzilla.mozilla.org mozilla.org

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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