Memory safety bugs present in Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141 and Thunderbird 141. 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 affects Firefox < 142, Firefox ESR < 140.2, Thunderbird < 142, and Thunderbird < 140.2.

Memory safety bugs present in Firefox 141 and Thunderbird 141. 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 affects Firefox < 142 and Thunderbird < 142.

'Denial-of-service due to out-of-memory in the Graphics: WebRender component.' This vulnerability affects Firefox < 142, Firefox ESR < 140.2, Thunderbird < 142, and Thunderbird < 140.2.

Memory safety bugs present in Firefox ESR 115.26, Firefox ESR 128.13, Thunderbird ESR 128.13, Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141 and Thunderbird 141. 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 affects Firefox < 142, Firefox ESR < 115.27, Firefox ESR < 128.14, Firefox ESR < 140.2, Thunderbird < 142, Thunderbird < 128.14, and Thunderbird < 140.2.

Uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 142, Firefox ESR < 128.14, Firefox ESR < 140.2, Thunderbird < 142, Thunderbird < 128.14, and Thunderbird < 140.2.

'Same-origin policy bypass in the Graphics: Canvas2D component.' This vulnerability affects Firefox < 142, Firefox ESR < 115.27, Firefox ESR < 128.14, Firefox ESR < 140.2, Thunderbird < 142, Thunderbird < 128.14, and Thunderbird < 140.2.

An attacker was able to perform memory corruption in the GMP process which processes encrypted media. This process is also heavily sandboxed, but represents slightly different privileges from the content process. This vulnerability affects Firefox < 142, Firefox ESR < 115.27, Firefox ESR < 128.14, Firefox ESR < 140.2, Thunderbird < 142, Thunderbird < 128.14, and Thunderbird < 140.2.

Memory safety bugs present in 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 affects Firefox < 141 and Thunderbird < 141.

Focus incorrectly truncated URLs towards the beginning instead of around the origin. This vulnerability affects Firefox < 141 and Thunderbird < 141.

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 affects Firefox < 141, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

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 affects Firefox < 141, Firefox ESR < 140.1, Thunderbird < 141, and Thunderbird < 140.1.

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 affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

The JavaScript engine did not handle closed generators correctly and it was possible to resume them leading to a nullptr deref. This vulnerability affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

In some cases search terms persisted in the URL bar even after navigating away from the search page. This vulnerability affects Firefox < 141, Firefox ESR < 140.1, Thunderbird < 141, and Thunderbird < 140.1.

Firefox ignored paths when checking the validity of navigations in a frame. This vulnerability affects Firefox < 141, Firefox ESR < 140.1, Thunderbird < 141, and Thunderbird < 140.1.

XSLT document loading did not correctly propagate the source document which bypassed its CSP. This vulnerability affects Firefox < 141, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

The `username:password` part was not correctly stripped from URLs in CSP reports potentially leaking HTTP Basic Authentication credentials. This vulnerability affects Firefox < 141, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

Insufficient escaping in the “Copy as cURL” feature could potentially be used to trick a user into executing unexpected code. This vulnerability affects Firefox < 141, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

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 affects Firefox < 141, Firefox ESR < 140.1, Thunderbird < 141, and Thunderbird < 140.1.

Firefox cached CORS preflight responses across IP address changes. This allowed circumventing CORS with DNS rebinding. This vulnerability affects Firefox < 141, Firefox ESR < 140.1, Thunderbird < 141, and Thunderbird < 140.1.

Firefox executed `javascript:` URLs when used in `object` and `embed` tags. This vulnerability affects Firefox < 141, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

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 affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

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 affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

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 affects Firefox < 140 and Thunderbird < 140.

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 affects Firefox < 140 and Thunderbird < 140.

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 affects Firefox < 140 and Thunderbird < 140.

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 affects Firefox < 140 and Thunderbird < 140.

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 affects Firefox < 140 and Thunderbird < 140.

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 affects Firefox < 140 and Thunderbird < 140.

When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `&lt;embed&gt;` or `&lt;object&gt;` tag, potentially making a website vulnerable to a cross-site scripting attack. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

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 affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

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 affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

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 affects Firefox < 140, Firefox ESR < 115.25, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

A use-after-free in FontFaceSet resulted in a potentially exploitable crash. This vulnerability affects Firefox < 140, Firefox ESR < 115.25, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

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 affects Thunderbird < 128.11.1 and Thunderbird < 139.0.2.

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 affects Firefox < 139 and Thunderbird < 139.

Previewing a response in Devtools ignored CSP headers, which could have allowed content injection attacks. This vulnerability affects Firefox < 139 and Thunderbird < 139.

In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vulnerability affects Firefox < 139 and Thunderbird < 139.

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 affects Firefox ESR < 128.11 and Thunderbird < 128.11.

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 affects Firefox < 139, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.

A clickjacking vulnerability could have been used to trick a user into leaking saved payment card details to a malicious page. This vulnerability affects Firefox < 139, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.

Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability affects Firefox < 139, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.

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 affects Firefox < 139, Firefox ESR < 115.24, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.

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 affects Firefox < 139, Firefox ESR < 115.24, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.

Error handling for script execution was incorrectly isolated from web content, which could have allowed cross-origin leak attacks. This vulnerability affects Firefox < 139, Firefox ESR < 115.24, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.

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.

An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2.

An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2.

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 affects Thunderbird < 128.10.1 and Thunderbird < 138.0.1.

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 affects Thunderbird < 128.10.1 and Thunderbird < 138.0.1.