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
- 9.6 Critical severity
Firefox: Use After Free
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
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
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
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
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
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
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
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.
- 7.5 High severity
Thunderbird: URL Redirection to Untrusted Site
When logging in to a Matrix account, Thunderbird used the homeserver address provided in the server's login response without validating it. A malicious or compromised homeserver could provide a file: URL, causing Thunderbird to send all further Matrix requests
- 8.8 High severity
Clicking a news: or snews: link that referenced a message-ID made Thunderbird connect, without…
Clicking a news: or snews: link that referenced a message-ID made Thunderbird connect, without asking, to the host and port given in the link, even if it was not a configured news server. Line breaks in the message-ID were sent to the server unmodified, so a c
- 9.1 Critical severity
Thunderbird: URL Redirection to Untrusted Site
When looking for calendars in a directory on a server, during account setup or when adding a new network calendar, Thunderbird accepted calendar locations pointing to other servers, local files or network shares. A malicious server, or a network attacker when
- 8.1 High severity
Thunderbird: Exposure of Sensitive Information to an Unauthorized Actor
Thunderbird's check that prevents mailbox: URLs from accessing files on remote Windows network shares could be bypassed using extended-length UNC paths. Displaying a specially crafted email could cause Thunderbird to connect to an SMB server chosen by the atta
- 7.5 High severity
Thunderbird: Exposure of Sensitive Information to an Unauthorized Actor
When replying to, forwarding, or editing a crafted email message as new, Thunderbird could embed parts of a different message stored in the same folder into the message being composed, without showing a blocked content warning. If the user sent the message, th
- 8.8 High severity
Firefox: Use After Free
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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.