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
- 8.1 High severity
Firefox: Incorrect Default Permissions
It was possible for a web extension with minimal permissions to create a `StreamFilter` which could be used to read and modify the response body of requests on any site. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thund
- 8.1 High severity
Firefox: Improper Restriction of Rendered UI Layers or Frames
A select option could partially obscure security prompts. This could be used by a malicious site to trick a user into granting permissions. *This issue only affects Android versions of Firefox.* This vulnerability affects Firefox < 129.
- 8.8 High severity
Firefox: Out-of-bounds Read
Editor code failed to check an attribute value. This could have led to an out-of-bounds read. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.
- 8.8 High severity
Firefox: Improper Handling of Exceptional Conditions
Incomplete WebAssembly exception handing could have led to a use-after-free. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.
- 8.8 High severity
Firefox: Access of Resource Using Incompatible Type
A type confusion bug in WebAssembly could be leveraged by an attacker to potentially achieve code execution. This vulnerability affects Firefox < 129, Firefox ESR < 128.1, and Thunderbird < 128.1.
- 9.6 Critical severity
Firefox: Out-of-bounds Write
Insufficient checks when processing graphics shared memory could have led to memory corruption. This could be leveraged by an attacker to perform a sandbox escape. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird
- 8.8 High severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 127 and Thunderbird 127. 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 affects Firefox < 12
- 9.8 Critical severity
Firefox: Sensitive Cookie with Improper SameSite Attribute
A nested iframe, triggering a cross-site navigation, could send SameSite=Strict or Lax cookies. This vulnerability affects Firefox < 128 and Thunderbird < 128.
- 8.8 High severity
Firefox: Release of Invalid Pointer or Reference
It was possible to prevent a user from exiting pointerlock when pressing escape and to overlay customValidity notifications from a `<select>` element over certain permission prompts. This could be used to confuse a user into giving a site unintended perm
- 8.2 High severity
Firefox: Out-of-bounds Read
Clipboard code failed to check the index on an array access. This could have led to an out-of-bounds read. This vulnerability affects Firefox < 128 and Thunderbird < 128.
- 7.5 High severity
Firefox: Buffer Copy without Checking Size of Input
Memory safety bugs present in Firefox 127, Firefox ESR 115.12, and Thunderbird 115.12. 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 vulnerabil
- 7.4 High severity
Firefox: Use of Out-of-range Pointer Offset
In an out-of-memory scenario an allocation could fail but free would have been called on the pointer afterwards leading to memory corruption. This vulnerability affects Firefox < 128, Firefox ESR < 115.13, Thunderbird < 115.13, and Thunderbird < 128.
- 9.8 Critical severity
Firefox: Improper Control of Generation of Code
A mismatch between allocator and deallocator could have led to memory corruption. This vulnerability affects Firefox < 128, Firefox ESR < 115.13, Thunderbird < 115.13, and Thunderbird < 128.
- 7.5 High severity
Firefox: Use After Free
Memory corruption in the networking stack could have led to a potentially exploitable crash. This vulnerability affects Firefox < 125, Firefox ESR < 115.12, and Thunderbird < 115.12.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 126. 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 affects Firefox < 127.
- 7.0 High severity
Firefox: Access of Memory Location Before Start of Buffer
Memory safety bugs present in Firefox 126, Firefox ESR 115.11, and Thunderbird 115.11. 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 vulnerabil
- 9.8 Critical severity
Firefox: Improper Handling of Case Sensitivity
In violation of spec, cookie prefixes such as `__Secure` were being ignored if they were not correctly capitalized - by spec they should be checked with a case-insensitive comparison. This could have resulted in the browser not correctly honoring the behaviors
- 8.6 High severity
Firefox: Out-of-bounds Write
By manipulating the text in an `<input>` tag, an attacker could have caused corrupt memory leading to a potentially exploitable crash. This vulnerability affects Firefox < 127, Firefox ESR < 115.12, and Thunderbird < 115.12.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
If an out-of-memory condition occurs at a specific point using allocations in the probabilistic heap checker, an assertion could have been triggered, and in rarer situations, memory corruption could have occurred. This vulnerability affects Firefox < 127.
- 7.5 High severity
Firefox: Use After Free
An attacker could have caused a use-after-free in the JavaScript engine to read memory in the JavaScript string section of the heap. This vulnerability affects Firefox < 127.
- 8.1 High severity
Firefox: Use After Free
If a garbage collection was triggered at the right time, a use-after-free could have occurred during object transplant. This vulnerability affects Firefox < 127, Firefox ESR < 115.12, and Thunderbird < 115.12.
- 9.8 Critical severity
Firefox: Improper Handling of Overlap Between Protected Memory Ranges
Memory safety bugs present in Firefox 125. 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 affects Firefox < 126.
- 8.8 High severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 125, Firefox ESR 115.10, and Thunderbird 115.10. 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 vulnerabil
- 7.5 High severity
Firefox: URL Redirection to Untrusted Site
When a network error occurred during page load, the prior content could have remained in view with a blank URL bar. This could have been used to obfuscate a spoofed web site. This vulnerability affects Firefox < 126.
- 8.6 High severity
Firefox: Use After Free
A memory allocation check was missing which would lead to a use-after-free if the allocation failed. This could have triggered a crash or potentially be leveraged to achieve code execution. This vulnerability affects Firefox < 126.
- 8.8 High severity
Firefox: Use After Free
When saving a page to PDF, certain font styles could have led to a potential use-after-free crash. This vulnerability affects Firefox < 126, Firefox ESR < 115.11, and Thunderbird < 115.11.
- 8.1 High severity
Firefox: Use of a Broken or Risky Cryptographic Algorithm
Web application manifests were stored by using an insecure MD5 hash which allowed for a hash collision to overwrite another application's manifest. This could have been exploited to run arbitrary code in another application's context. *This issue only affects
- 8.8 High severity
Firefox: Improper Check for Unusual or Exceptional Conditions
A type check was missing when handling fonts in PDF.js, which would allow arbitrary JavaScript execution in the PDF.js context. This vulnerability affects Firefox < 126, Firefox ESR < 115.11, and Thunderbird < 115.11.
- 8.1 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Memory safety bugs present in Firefox 124. 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 affects Firefox < 125.
- 8.1 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Memory safety bug present in Firefox 124, Firefox ESR 115.9, and Thunderbird 115.9. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox <
- 9.8 Critical severity
Firefox: Unrestricted Upload of File with Dangerous Type
The executable file warning was not presented when downloading .xrm-ms files. *Note: This issue only affected Windows operating systems. Other operating systems are unaffected.* This vulnerability affects Firefox < 125, Firefox ESR < 115.10, and Thunderbird <
- 7.8 High severity
Firefox: Use After Free
The JIT created incorrect code for arguments in certain cases. This led to potential use-after-free crashes during garbage collection. This vulnerability affects Firefox < 125, Firefox ESR < 115.10, and Thunderbird < 115.10.
- 8.8 High severity
Firefox: Use After Free
A use-after-free could occur during WASM execution if garbage collection ran during the creation of an array. This vulnerability affects Firefox < 125.
- 8.8 High severity
Firefox: Out-of-bounds Read
In some code patterns the JIT incorrectly optimized switch statements and generated code with out-of-bounds-reads. This vulnerability affects Firefox < 125, Firefox ESR < 115.10, and Thunderbird < 115.10.
- 7.5 High severity
Firefox: Use After Free
A use-after-free could result if a JavaScript realm was in the process of being initialized when a garbage collection started. This vulnerability affects Firefox < 125.
- 7.5 High severity
Firefox: Symbolic Name not Mapping to Correct Object
GetBoundName could return the wrong version of an object when JIT optimizations were applied. This vulnerability affects Firefox < 125, Firefox ESR < 115.10, and Thunderbird < 115.10.
- 8.4 High severity
Firefox: Inclusion of Web Functionality from an Untrusted Source
An attacker was able to inject an event handler into a privileged object that would allow arbitrary JavaScript execution in the parent process. Note: This vulnerability affects Desktop Firefox only, it does not affect mobile versions of Firefox. This vulnerabi
- 9.8 Critical severity
Firefox: Out-of-bounds Read
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by fooling range-based bounds check elimination. This vulnerability affects Firefox < 124.0.1.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 123. 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 affects Firefox < 124.
- 8.8 High severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 123, Firefox ESR 115.8, and Thunderbird 115.8. 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 vulnerabilit