Mozilla Firefox vulnerabilities

CVE-2026-4711 [CRITICAL] CWE-416 CVE-2026-4711: Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4692 [CRITICAL] CVE-2026-4692: Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4710 [CRITICAL] CWE-119 CVE-2026-4710: Incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox Incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4721 [CRITICAL] CWE-120 CVE-2026-4721: Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. 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 was fixed in Firefox 149, Firefox ESR 115.34, Fire

CVE-2026-4729 [CRITICAL] CWE-120 CVE-2026-4729: Memory safety bugs present in Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of Memory safety bugs present in Firefox 148 and Thunderbird 148. 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 was fixed in Firefox 149 and Thunderbird 149.

CVE-2026-4716 [CRITICAL] CWE-908 CVE-2026-4716: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnera Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4696 [CRITICAL] CWE-416 CVE-2026-4696: Use-after-free in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 149, Use-after-free in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4720 [CRITICAL] CWE-120 CVE-2026-4720: Memory safety bugs present in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird Memory safety bugs present in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. 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 was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thun

CVE-2026-4715 [CRITICAL] CWE-908 CVE-2026-4715: Uninitialized memory in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 14 Uninitialized memory in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4724 [CRITICAL] CWE-758 CVE-2026-4724: Undefined behavior in the Audio/Video component. This vulnerability was fixed in Firefox 149 and Thu Undefined behavior in the Audio/Video component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.

CVE-2026-4723 [CRITICAL] CWE-416 CVE-2026-4723: Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 149 and T Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.

CVE-2026-4705 [CRITICAL] CWE-758 CVE-2026-4705: Undefined behavior in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 149, Undefined behavior in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4690 [HIGH] CWE-190 CVE-2026-4690: Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This v Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4714 [HIGH] CWE-754 CVE-2026-4714: Incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox Incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4684 [HIGH] CWE-362 CVE-2026-4684: Race condition, use-after-free in the Graphics: WebRender component. This vulnerability was fixed in Race condition, use-after-free in the Graphics: WebRender component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4694 [HIGH] CWE-190 CVE-2026-4694: Incorrect boundary conditions, integer overflow in the Graphics component. This vulnerability was fi Incorrect boundary conditions, integer overflow in the Graphics component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4719 [HIGH] CWE-754 CVE-2026-4719: Incorrect boundary conditions in the Graphics: Text component. This vulnerability was fixed in Firef Incorrect boundary conditions in the Graphics: Text component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4686 [HIGH] CWE-754 CVE-2026-4686: Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability was fixed in F Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4712 [HIGH] CWE-200 CVE-2026-4712: Information disclosure in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Information disclosure in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4713 [HIGH] CWE-754 CVE-2026-4713: Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 149 Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.