Mozilla vulnerabilities
We track 912 vulnerabilities in Mozilla products across 22 products. 911 are rated high or critical, and 15 have been exploited in real attacks. The most recent was published on November 10, 2026.
Latest Mozilla vulnerabilities
- 8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.1 Critical severity
Firefox: Protection Mechanism Failure
Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Protection Mechanism Failure
Mitigation bypass in the Popup Blocker component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Improper Privilege Management
Privilege escalation in the Enterprise Policies component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.0 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Incorrect boundary conditions in the Safe Browsing component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.6 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Improper Privilege Management
Privilege escalation in the Session Restore component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the Internationalization component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.3 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Incorrect boundary conditions in the DOM: Editor component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.1 Critical severity
Firefox: Protection Mechanism Failure
Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Improper Privilege Management
Privilege escalation in the DevTools component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Improper Privilege Management
Privilege escalation in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use of Uninitialized Variable
Privilege escalation due to uninitialized memory in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.0 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Improper Privilege Management
Privilege escalation in the Crash Reporting component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.6 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Sandbox escape due to incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 7.5 High severity
Firefox: Exposure of Sensitive Information to an Unauthorized Actor
Information disclosure in the Networking: HTTP component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Buffer Copy without Checking Size of Input
Privilege escalation due to incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 7.5 High severity
Firefox: Concurrent Execution using Shared Resource with Improper Synchronization
Race condition in the DOM: Content Processes component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.1 Critical severity
Firefox: Protection Mechanism Failure
Mitigation bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.1 Critical severity
Firefox: Protection Mechanism Failure
Mitigation bypass in the Remote Settings Client component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
- 9.6 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Thunderbird 140.17, Firefox 156, Firefox ESR 153.3, Thunderbird 156, Thunderbird 153.3, Firefox ESR 115.42, and Firefox ESR 140.17.
- 9.6 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Sandbox escape due to invalid pointer in the Graphics component. This vulnerability was fixed in Firefox 156, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the SVG component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the DOM: Streams component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the DOM: Navigation component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the SVG component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the XML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the DOM: HTML Parser component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Buffer Copy without Checking Size of Input
Privilege escalation due to incorrect boundary conditions in the Graphics: WebRender component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.1 High severity
Firefox: Protection Mechanism Failure
Mitigation bypass in the Remote Settings Client component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 9.6 Critical severity
Firefox: Protection Mechanism Failure
Sandbox escape in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Improper Privilege Management
Privilege escalation in the DOM: Service Workers component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- 8.8 High severity
Firefox: Use After Free
Use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 156, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.