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 Rendered UI Layers or Frames
Data was not properly sanitized when decoding a QUIC ACK frame; this could have led to unrestricted memory consumption and a crash. This vulnerability affects Firefox < 124.
- 8.1 High severity
Firefox: Use After Free
If an attacker could find a way to trigger a particular code path in `SafeRefPtr`, it could have triggered a crash or potentially be leveraged to achieve code execution. This vulnerability affects Firefox < 124, Firefox ESR < 115.9, and Thunderbird < 115.9.
- 8.4 High severity
Firefox: Integer Overflow to Buffer Overflow
`AppendEncodedAttributeValue(), ExtraSpaceNeededForAttrEncoding()` and `AppendEncodedCharacters()` could have experienced integer overflows, causing underallocation of an output buffer leading to an out of bounds write. This vulnerability affects Firefox < 124
- 8.1 High severity
Firefox: Write-what-where Condition
Return registers were overwritten which could have allowed an attacker to execute arbitrary code. *Note:* This issue only affected Armv7-A systems. Other operating systems are unaffected. This vulnerability affects Firefox < 124, Firefox ESR < 115.9, and Thund
- 7.5 High severity
Thunderbird: Insecure Storage of Sensitive Information
The encrypted subject of an email message could be incorrectly and permanently assigned to an arbitrary other email message in Thunderbird's local cache. Consequently, when replying to the contaminated email message, the user might accidentally leak the confid
- 7.8 High severity
Firefox for iOS: Improper Neutralization of Script in Attributes in a Web Page
An attacker could have executed unauthorized scripts on top origin sites using a JavaScript URI when opening an external URL with a custom Firefox scheme. This vulnerability affects Firefox for iOS < 123.
- 7.1 High severity
Firefox for iOS: Improper Neutralization of Script-Related HTML Tags in a Web Page
Using an AMP url with a canonical element, an attacker could have executed JavaScript from an opened bookmarked page. This vulnerability affects Firefox for iOS < 123.
- 8.1 High severity
Focus for iOS: Time-of-check Time-of-use (TOCTOU) Race Condition
An attacker could have executed unauthorized scripts on top origin sites using a JavaScript URI when opening an external URL with a custom Firefox scheme and a timeout race condition. This vulnerability affects Focus for iOS < 122.
- 8.1 High severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 122. 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 < 123.
- 8.3 High severity
Firefox: Authentication Bypass by Spoofing
When opening a website using the `firefox://` protocol handler, SameSite cookies were not properly respected. This vulnerability affects Firefox < 123.
- 9.8 Critical severity
Firefox: Insufficient Verification of Data Authenticity
The `fetch()` API and navigation incorrectly shared the same cache, as the cache key did not include the optional headers `fetch()` may contain. Under the correct circumstances, an attacker may have been able to poison the local browser cache by priming it wit
- 8.1 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Memory safety bugs present in Firefox 122, Firefox ESR 115.7, and Thunderbird 115.7. 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
- 7.5 High severity
Firefox: Incorrect Conversion between Numeric Types
Incorrect code generation could have led to unexpected numeric conversions and potential undefined behavior.*Note:* This issue only affects 32-bit ARM devices. This vulnerability affects Firefox < 123, Firefox ESR < 115.8, and Thunderbird < 115.8.
- 7.5 High severity
Firefox: Out-of-bounds Read
When storing and re-accessing data on a networking channel, the length of buffers may have been confused, resulting in an out-of-bounds memory read. This vulnerability affects Firefox < 123, Firefox ESR < 115.8, and Thunderbird < 115.8.
- 8.8 High severity
Firefox: Improper Control of Generation of Code
Memory safety bugs present in Firefox 121, Firefox ESR 115.6, and Thunderbird 115.6. 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
- 8.8 High severity
Firefox: Improper Privilege Management
A malicious devtools extension could have been used to escalate privileges. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.
- 8.8 High severity
Firefox: User Interface (UI) Misrepresentation of Critical Information
A bug in popup notifications delay calculation could have made it possible for an attacker to trick a user into granting permissions. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.
- 8.8 High severity
Firefox: Out-of-bounds Write
The WebAudio `OscillatorNode` object was susceptible to a stack buffer overflow. This could have led to a potentially exploitable crash. This vulnerability affects Firefox < 122.
- 7.5 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
In some circumstances, JIT compiled code could have dereferenced a wild pointer value. This could have led to an exploitable crash. This vulnerability affects Firefox < 122.
- 7.5 High severity
Firefox: Unchecked Return Value
An unchecked return value in TLS handshake code could have caused a potentially exploitable crash. This vulnerability affects Firefox < 122, Firefox ESR < 115.9, and Thunderbird < 115.9.
- 7.5 High severity
Focus for iOS: Concurrent Execution using Shared Resource with Improper Synchronization
Using a javascript: URI with a setTimeout race condition, an attacker can execute unauthorized scripts on top origin sites in urlbar. This bypasses security measures, potentially leading to arbitrary code execution or unauthorized actions within the user's loa
- 8.8 High severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 120. 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 < 121.
- 8.8 High severity
Firefox: Improper Handling of Exceptional Conditions
TypedArrays can be fallible and lacked proper exception handling. This could lead to abuse in other APIs which expect TypedArrays to always succeed. This vulnerability affects Firefox < 121.
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
Memory safety bugs present in Firefox 120, Firefox ESR 115.5, and Thunderbird 115.5. 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
- 8.8 High severity
Firefox ESR: Use After Free
A use-after-free was identified in the `nsDNSService::Init`. This issue appears to manifest rarely during start-up. This vulnerability affects Firefox ESR < 115.6 and Thunderbird < 115.6.
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
The `nsWindow::PickerOpen(void)` method was susceptible to a heap buffer overflow when running in headless mode. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.
- 8.8 High severity
Firefox ESR: Use After Free
A use-after-free condition affected TLS socket creation when under memory pressure. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
Firefox was susceptible to a heap buffer overflow in `nsTextFragment` due to insufficient OOM handling. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
The WebGL `DrawElementsInstanced` method was susceptible to a heap buffer overflow when used on systems with the Mesa VM driver. This issue could allow an attacker to perform remote code execution and sandbox escape. This vulnerability affects Firefox ESR < 11
- 8.8 High severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 119. 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 < 120.
- 8.8 High severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 119, Firefox ESR 115.4, and Thunderbird 115.4. 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
- 8.8 High severity
Firefox: Use After Free
Ownership mismanagement led to a use-after-free in ReadableByteStreams This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 118. 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 < 119.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 118, Firefox ESR 115.3, and Thunderbird 115.3. 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
- 7.5 High severity
Firefox: Use After Free
During garbage collection extra operations were performed on a object that should not be. This could have led to a potentially exploitable crash. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.
- 7.5 High severity
Firefox: Uncontrolled Resource Consumption
Drivers are not always robust to extremely large draw calls and in some cases this scenario could have led to a crash. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.
- 8.8 High severity
Google Chromium libvpx Heap Buffer Overflow Exploited
Heap buffer overflow in vp8 encoding in libvpx in Google Chrome prior to 117.0.5938.132 and libvpx 1.13.1 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High)
- 9.8 Critical severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 117, Firefox ESR 115.2, and Thunderbird 115.2. 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
- 9.8 Critical severity
Firefox: Use After Free
During process shutdown, it was possible that an `ImageBitmap` was created that would later be used after being freed from a different codepath, leading to a potentially exploitable crash. This vulnerability affects Firefox < 118.
- 9.8 Critical severity
Firefox: Use After Free
If Windows failed to duplicate a handle during process creation, the sandbox code may have inadvertently freed a pointer twice, resulting in a use-after-free and a potentially exploitable crash. *This bug only affects Firefox on Windows when run in non-standar