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
- 7.5 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- 7.5 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- 7.5 High severity
Firefox: Use of Uninitialized Variable
Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- 7.5 High severity
Firefox: Improper Privilege Management
Privilege escalation in the Graphics: WebRender component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- 7.5 High severity
Firefox: Use of Uninitialized Resource
Information disclosure due to uninitialized memory in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- 7.5 High severity
Firefox: Use of Uninitialized Variable
Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- 7.5 High severity
Firefox: Use After Free
Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
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
- 9.8 Critical severity
Firefox: Out-of-bounds Write
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 a
- 8.8 High severity
Firefox: Integer Overflow or Wraparound
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.
- 8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Memory safety bugs present in Firefox ESR 115.34.0, 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 b
- 8.2 High severity
Thunderbird: Buffer Over-read
A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially c
- 7.5 High severity
Firefox: Buffer Copy without Checking Size of Input
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
- 7.5 High severity
Firefox: Buffer Copy without Checking Size of Input
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
- 7.5 High severity
Firefox: Buffer Copy without Checking Size of Input
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 cod
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
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.
- 8.1 High severity
Firefox: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
Undefined behavior in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 9.1 Critical severity
Firefox: Use of Uninitialized Resource
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.
- 9.1 Critical severity
Firefox: Use of Uninitialized Resource
Uninitialized memory in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
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.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 7.5 High severity
Firefox: Exposure of Sensitive Information to an Unauthorized Actor
Information disclosure in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 9.8 Critical severity
Firefox: Use After Free
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.
- 9.8 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
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.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
Incorrect boundary conditions in the Audio/Video: GMP component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
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.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
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.
- 9.8 Critical severity
Firefox: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
Undefined behavior in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 7.5 High severity
Firefox: Uncontrolled Resource Consumption
Denial-of-service in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 9.8 Critical severity
Firefox: Access of Resource Using Incompatible Type
JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 9.8 Critical severity
Firefox: Use After Free
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.
- 9.8 Critical severity
Firefox: Authentication Bypass Using an Alternate Path or Channel
Mitigation bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
Incorrect boundary conditions 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.
- 9.8 Critical severity
Firefox: Access of Resource Using Incompatible Type
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.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 9.8 Critical severity
Firefox: Use After Free
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.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 7.5 High severity
Firefox: Integer Overflow or Wraparound
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.
- 7.5 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.