Calling `PK11_Encrypt()` in NSS using CKM_CHACHA20 and the same buffer for input and output can result in plaintext on an Intel Sandy Bridge processor. In Firefox this only affects the QUIC header protection feature when the connection is using the ChaCha20-Poly1305 cipher suite. The most likely outcome is connection failure, but if the connection persists despite the high packet loss it could be possible for a network observer to identify packets as coming from the same source despite a network path change. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, and Firefox ESR < 128.1.

Incorrect garbage collection interaction could have led to a use-after-free. This vulnerability affects Firefox < 129.

The date picker could partially obscure security prompts. This could be used by a malicious site to trick a user into granting permissions. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

Incorrect garbage collection interaction in IndexedDB could have led to a use-after-free. This vulnerability affects Firefox < 129, Firefox ESR < 128.1, and Thunderbird < 128.1.

Unexpected marking work at the start of sweeping could have led to a use-after-free. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

ANGLE failed to initialize parameters which led to reading from uninitialized memory. This could be leveraged to leak sensitive data from memory. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

It was possible for a web extension with minimal permissions to create a `StreamFilter` which could be used to read and modify the response body of requests on any site. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

Firefox adds web-compatibility shims in place of some tracking scripts blocked by Enhanced Tracking Protection. On a site protected by Content Security Policy in "strict-dynamic" mode, an attacker able to inject an HTML element could have used a DOM Clobbering attack on some of the shims and achieved XSS, bypassing the CSP strict-dynamic protection. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, and Firefox ESR < 128.1.

Editor code failed to check an attribute value. This could have led to an out-of-bounds read. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

Incomplete WebAssembly exception handing could have led to a use-after-free. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

A type confusion bug in WebAssembly could be leveraged by an attacker to potentially achieve code execution. This vulnerability affects Firefox < 129, Firefox ESR < 128.1, and Thunderbird < 128.1.

Insufficient checks when processing graphics shared memory could have led to memory corruption. This could be leveraged by an attacker to perform a sandbox escape. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

Select options could obscure the fullscreen notification dialog. This could be used by a malicious site to perform a spoofing attack. This vulnerability affects Firefox < 129, Firefox ESR < 128.1, and Thunderbird < 128.1.

Form validation popups could capture escape key presses. Therefore, spamming form validation messages could be used to prevent users from exiting full-screen mode. This vulnerability affects Firefox < 128 and Thunderbird < 128.

When almost out-of-memory an elliptic curve key which was never allocated could have been freed again. This vulnerability affects Firefox < 128 and Thunderbird < 128.

It was possible to move the cursor using pointerlock from an iframe. This allowed moving the cursor outside of the viewport and the Firefox window. This vulnerability affects Firefox < 128 and Thunderbird < 128.

By manipulating the fullscreen feature while opening a data-list, an attacker could have overlaid a text box over the address bar. This could have led to user confusion and possible spoofing attacks. This vulnerability affects Firefox < 127.

A website was able to detect when a user took a screenshot of a page using the built-in Screenshot functionality in Firefox. This vulnerability affects Firefox < 127.

By tricking the browser with a `X-Frame-Options` header, a sandboxed iframe could have presented a button that, if clicked by a user, would bypass restrictions to open a new window. This vulnerability affects Firefox < 127, Firefox ESR < 115.12, and Thunderbird < 115.12.

By monitoring the time certain operations take, an attacker could have guessed which external protocol handlers were functional on a user's system. This vulnerability affects Firefox < 127, Firefox ESR < 115.12, and Thunderbird < 115.12.