Mozilla Firefox vulnerabilities

CVE-2026-6774 [MEDIUM] CWE-693 CVE-2026-6774: Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150 and Th Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVE-2026-6777 [MEDIUM] CWE-20 CVE-2026-6777: Other issue in the Networking: DNS component. This vulnerability was fixed in Firefox 150 and Thunde Other issue in the Networking: DNS component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVE-2026-6779 [MEDIUM] CWE-20 CVE-2026-6779: Other issue in the JavaScript Engine component. This vulnerability was fixed in Firefox 150 and Thun Other issue in the JavaScript Engine component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVE-2026-6783 [MEDIUM] CWE-190 CVE-2026-6783: Incorrect boundary conditions, integer overflow in the Audio/Video: Playback component. This vulnera Incorrect boundary conditions, integer overflow in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVE-2026-6765 [MEDIUM] CWE-359 CVE-2026-6765: Information disclosure in the Form Autofill component. This vulnerability was fixed in Firefox 150, Information disclosure in the Form Autofill component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVE-2026-6764 [MEDIUM] CWE-119 CVE-2026-6764: Incorrect boundary conditions in the DOM: Device Interfaces component. This vulnerability was fixed Incorrect boundary conditions in the DOM: Device Interfaces component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVE-2026-6654 [MEDIUM] CWE-1341 thin-vec: mozilla/thin-vec: Memory corruption vulnerability via Double-Free/Use-After-Free thin-vec: mozilla/thin-vec: Memory corruption vulnerability via Double-Free/Use-After-Free A flaw was found in the `thin_vec` component of `mozilla/thin-vec`. This vulnerability involves a memory management error known as a Double-Free/Use-After-Free (UAF), which occurs in the `IntoIter::drop` and `ThinVec::clear` functions. When a specific error condition (a panic in `ptr:

CVE-2026-5734 [CRITICAL] CWE-787 CVE-2026-5734: Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thun Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2, Firefox ESR 140.9.1, Thunde

CVE-2026-5735 [CRITICAL] CWE-787 CVE-2026-5735: Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evi Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2 and Thunderbird 149.0.2.

CVE-2026-5732 [HIGH] CWE-190 CVE-2026-5732: Incorrect boundary conditions, integer overflow in the Graphics: Text component. This vulnerability Incorrect boundary conditions, integer overflow in the Graphics: Text component. This vulnerability was fixed in Firefox 149.0.2, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.

CVE-2026-5733 [HIGH] CWE-119 CVE-2026-5733: Incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Fir Incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 149.0.2 and Thunderbird 149.0.2.

CVE-2026-4691 [CRITICAL] CWE-416 CVE-2026-4691: Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4698 [CRITICAL] CWE-843 CVE-2026-4698: JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4700 [CRITICAL] CWE-288 CVE-2026-4700: Mitigation bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 149, Fi Mitigation bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4701 [CRITICAL] CWE-416 CVE-2026-4701: Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Fire Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4725 [CRITICAL] CWE-416 CVE-2026-4725: Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fix Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.

CVE-2026-4689 [CRITICAL] CWE-190 CVE-2026-4689: 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-2026-4717 [CRITICAL] CVE-2026-4717: Privilege escalation in the Netmonitor component. This vulnerability was fixed in Firefox 149, Firef Privilege escalation in the Netmonitor component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4702 [CRITICAL] CWE-843 CVE-2026-4702: JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2026-4688 [CRITICAL] CWE-416 CVE-2026-4688: Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.