Memory safety bugs present in Firefox 136 and Thunderbird 136. 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 and Thunderbird < 137.

After selecting a malicious Windows `.url` shortcut from the local filesystem, an unexpected file could be uploaded. *This bug only affects Firefox on Windows. Other operating systems are unaffected.* This vulnerability affects Firefox < 137 and Thunderbird < 137.

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.

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.

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.

An inconsistent comparator in xslt/txNodeSorter could have resulted in potentially exploitable out-of-bounds access. Only affected version 122 and later. This vulnerability affects Firefox < 136, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

It was possible to cause a use-after-free in the content process side of a WebTransport connection, leading to a potentially exploitable crash. This vulnerability affects Firefox < 136, Firefox ESR < 115.21, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

On Windows, a compromised content process could use bad StreamData sent over AudioIPC to trigger a use-after-free in the Browser process. This could have led to a sandbox escape. This vulnerability affects Firefox < 136, Firefox ESR < 115.21, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.