An attacker was able to achieve code execution in the content process by exploiting a use-after-free in Animation timelines. We have had reports of this vulnerability being exploited in the wild.

Chromium: CVE-2023-5217 Heap buffer overflow in vp8 encoding in libvpx

Chromium: CVE-2023-4863 Heap buffer overflow in WebP

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.

An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes.

An attacker was able to perform an out-of-bounds read or write on a JavaScript Promise object. This vulnerability affects Firefox ESR < 115.23.1.

An attacker was able to inject an event handler into a privileged object that would allow arbitrary JavaScript execution in the parent process. Note: This vulnerability affects Desktop Firefox only, it does not affect mobile versions of Firefox. This vulnerability affects Firefox < 124.0.1 and Firefox ESR < 115.9.1.

An attacker was able to perform an out-of-bounds read or write on a JavaScript object by fooling range-based bounds check elimination. This vulnerability affects Firefox < 124.0.1.