Firefox vulnerabilities

870 known vulnerabilities in Firefox from Mozilla. 869 are rated high or critical, and 15 have been exploited in real attacks. Each entry lists the affected versions and the release that fixes it, where the vendor has published one.

870vulnerabilities

253critical

616high

15exploited

8.7average CVSS score

Latest first

9.6 Critical severity
Firefox: Use After Free
CVE-2026-124861Nov 10, 2026Mozilla
Sandbox escape due to use-after-free in the Audio/Video: cubeb component. This vulnerability was fixed in Firefox 160, Firefox ESR 115.45, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
8.8 High severity
Firefox: Use After Free
CVE-2026-124860Nov 10, 2026Mozilla
Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 160, Firefox ESR 115.45, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
9.6 Critical severity
Firefox: Buffer Copy without Checking Size of Input
CVE-2026-124859Nov 10, 2026Mozilla
Sandbox escape due to incorrect boundary conditions in the Storage: Cache API component. This vulnerability was fixed in Firefox 160, Firefox ESR 115.45, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
8.8 High severity
Firefox: Use After Free
CVE-2026-124858Nov 10, 2026Mozilla
Use-after-free in the DOM: HTML Parser component. This vulnerability was fixed in Firefox 160, Firefox ESR 115.45, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
8.8 High severity
Firefox: Use After Free
CVE-2026-124857Nov 10, 2026Mozilla
Use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 160, Firefox ESR 115.45, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
8.8 High severity
Firefox: Buffer Copy without Checking Size of Input
CVE-2026-124856Nov 10, 2026Mozilla
Incorrect boundary conditions in the Networking: HTTP component. This vulnerability was fixed in Firefox 160, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
8.8 High severity
Firefox: Improper Privilege Management
CVE-2026-124854Nov 10, 2026Mozilla
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 160, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
9.6 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-124853Nov 10, 2026Mozilla
Sandbox escape due to incorrect boundary conditions in the Graphics: Text component. This vulnerability was fixed in Firefox 160, Firefox ESR 115.45, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
8.8 High severity
Firefox: Use After Free
CVE-2026-118024Oct 27, 2026Mozilla
Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 159, Thunderbird 159, Firefox ESR 153.7, and Thunderbird 153.7.
8.8 High severity
Firefox: Use After Free
CVE-2026-118021Oct 27, 2026Mozilla
Sandbox escape due to use-after-free in the XPCOM component. This vulnerability was fixed in Firefox 159, Thunderbird 159, Firefox ESR 153.7, and Thunderbird 153.7.
8.8 High severity
Firefox: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2026-118019Oct 27, 2026Mozilla
Race condition, use-after-free in the DOM: File component. This vulnerability was fixed in Firefox 159, Thunderbird 159, Firefox ESR 153.7, and Thunderbird 153.7.
8.8 High severity
Firefox: Use After Free
CVE-2026-118007Oct 27, 2026Mozilla
Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 159, Thunderbird 159, Firefox ESR 153.7, and Thunderbird 153.7.
8.1 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-118004Oct 27, 2026Mozilla
Incorrect boundary conditions in the CSS Transitions and Animations component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.1 High severity
Firefox: Exposure of Sensitive Information to an Unauthorized Actor
CVE-2026-118003Oct 27, 2026Mozilla
Information disclosure in the Networking: DNS component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.1 High severity
Firefox: Exposure of Sensitive Information to an Unauthorized Actor
CVE-2026-118002Oct 27, 2026Mozilla
Information disclosure due to race condition in the Networking component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.1 High severity
Firefox: Exposure of Sensitive Information to an Unauthorized Actor
CVE-2026-118000Oct 27, 2026Mozilla
Information disclosure in the Networking: HTTP component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Protection Mechanism Failure
CVE-2026-117998Oct 27, 2026Mozilla
Mitigation bypass in the DOM: Push Subscriptions component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
9.6 Critical severity
Firefox: Use After Free
CVE-2026-117997Oct 27, 2026Mozilla
Sandbox escape due to use-after-free in the Widget component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.1 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-117996Oct 27, 2026Mozilla
Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Improper Access Control
CVE-2026-117995Oct 27, 2026Mozilla
Privilege escalation in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Use After Free
CVE-2026-117994Oct 27, 2026Mozilla
Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Integer Overflow or Wraparound
CVE-2026-117993Oct 27, 2026Mozilla
Integer overflow in the Graphics: Text component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-117991Oct 27, 2026Mozilla
Incorrect boundary conditions in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
9.6 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-117990Oct 27, 2026Mozilla
Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
9.6 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-117988Oct 27, 2026Mozilla
Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
9.6 Critical severity
Firefox: Use After Free
CVE-2026-117985Oct 27, 2026Mozilla
Sandbox escape due to use-after-free in the Graphics component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-117984Oct 27, 2026Mozilla
Incorrect boundary conditions in the Layout: Scrolling and Overflow component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
9.8 Critical severity
Firefox: Use After Free
CVE-2026-117982Oct 27, 2026Mozilla
Invalid pointer in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
9.8 Critical severity
Firefox: Improper Privilege Management
CVE-2026-117981Oct 27, 2026Mozilla
Privilege escalation in the Toolkit component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-117979Oct 27, 2026Mozilla
Incorrect boundary conditions in the Graphics: WebRender component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.1 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-117978Oct 27, 2026Mozilla
Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.1 High severity
Firefox: Origin Validation Error
CVE-2026-117976Oct 27, 2026Mozilla
Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Use After Free
CVE-2026-117975Oct 27, 2026Mozilla
Sandbox escape due to invalid pointer in the Graphics: WebRender component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Use After Free
CVE-2026-117974Oct 27, 2026Mozilla
Use-after-free in the XML component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Use After Free
CVE-2026-117973Oct 27, 2026Mozilla
Use-after-free in the Networking: DNS component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
9.6 Critical severity
Firefox: Use After Free
CVE-2026-117971Oct 27, 2026Mozilla
Sandbox escape due to use-after-free in the Print Preview component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2026-117970Oct 27, 2026Mozilla
Race condition in the Disability Access APIs component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Access of Uninitialized Pointer
CVE-2026-117969Oct 27, 2026Mozilla
Invalid pointer in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Use After Free
CVE-2026-117968Oct 27, 2026Mozilla
Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
8.8 High severity
Firefox: Protection Mechanism Failure
CVE-2026-117967Oct 27, 2026Mozilla
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.