Leaking of file descriptors from the fork server to web content processes could allow for privilege escalation attacks. This vulnerability affects Firefox < 137 and Thunderbird < 137.

An attacker could read 32 bits of values spilled onto the stack in a JIT compiled function. This vulnerability affects Firefox < 137 and Thunderbird < 137.

Memory safety bugs present in Firefox 136, Thunderbird 136, Firefox ESR 128.8, and Thunderbird 128.8. 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 < 137, Firefox ESR < 128.9, Thunderbird < 137, and Thunderbird < 128.9.

A crafted URL containing specific Unicode characters could have hidden the true origin of the page, resulting in a potential spoofing attack. This vulnerability affects Firefox < 137, Firefox ESR < 128.9, Thunderbird < 137, and Thunderbird < 128.9.

JavaScript code running while transforming a document with the XSLTProcessor could lead to a use-after-free. This vulnerability affects Firefox < 137, Firefox ESR < 115.22, Firefox ESR < 128.9, Thunderbird < 137, and Thunderbird < 128.9.

Following the recent Chrome sandbox escape (CVE-2025-2783), various Firefox developers identified a similar pattern in our IPC code. A compromised child process could cause the parent process to return an unintentionally powerful handle, leading to a sandbox escape. The original vulnerability was being exploited in the wild. *This only affects Firefox on Windows. Other operating systems are unaffected.* This vulnerability affects Firefox < 136.0.4, Firefox ESR < 128.8.1, and Firefox ESR < 115.21.1.

Malicious websites utilizing a server-side redirect to an internal error page could result in a spoofed website URL This vulnerability affects Firefox for iOS < 136.

Scanning certain QR codes that included text with a website URL could allow the URL to be opened without presenting the user with a confirmation alert first This vulnerability affects Firefox for iOS < 136.

Websites redirecting to a non-HTTP scheme URL could allow a website address to be spoofed for a malicious page This vulnerability affects Firefox for iOS < 136.

Memory safety bugs present in Firefox 135 and Thunderbird 135. 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 < 136 and Thunderbird < 136.

When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string This vulnerability affects Firefox < 136 and Thunderbird < 136.

Under certain circumstances, a user opt-in setting that Focus should require authentication before use could have been be bypassed (distinct from CVE-2025-0245). This vulnerability affects Firefox < 136.

A select option could partially obscure the confirmation prompt shown before launching external apps. This could be used to trick a user in to launching an external app unexpectedly. *This issue only affects Android versions of Firefox.* This vulnerability affects Firefox < 136.

Android apps can load web pages using the Custom Tabs feature. This feature supports a transition animation that could have been used to trick a user into granting sensitive permissions by hiding what the user was actually clicking. This vulnerability affects Firefox < 136.

Memory safety bugs present in Firefox 135, Thunderbird 135, Firefox ESR 128.7, and Thunderbird 128.7. 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 < 136, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

Memory safety bugs present in Firefox 135, Thunderbird 135, Firefox ESR 115.20, Firefox ESR 128.7, and Thunderbird 128.7. 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 < 136, Firefox ESR < 115.21, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

jar: URLs retrieve local file content packaged in a ZIP archive. The null and everything after it was ignored when retrieving the content from the archive, but the fake extension after the null was used to determine the type of content. This could have been used to hide code in a web extension disguised as something else like an image. This vulnerability affects Firefox < 136, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

A web page could trick a user into setting that site as the default handler for a custom URL protocol. This vulnerability affects Firefox < 136, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

It was possible to interrupt the processing of a RegExp bailout and run additional JavaScript, potentially triggering garbage collection when the engine was not expecting it. This vulnerability affects Firefox < 136, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

On 64-bit CPUs, when the JIT compiles WASM i32 return values they can pick up bits from left over memory. This can potentially cause them to be treated as a different type. This vulnerability affects Firefox < 136, Firefox ESR < 115.21, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.