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 Control of Generation of Code
A bug in WebAssembly code generation could have lead to a crash. It may have been possible for an attacker to leverage this to achieve code execution. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
- 8.8 High severity
Firefox: Use After Free
An attacker could have caused a use-after-free via the Custom Highlight API, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
- 9.8 Critical severity
Firefox: Use After Free
An attacker could have caused a use-after-free via crafted XSLT data, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 133 and Thunderbird 133. 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
- 7.7 High severity
Firefox: Missing Release of Memory after Effective Lifetime
When segmenting specially crafted text, segmentation would corrupt memory leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.
- 9.1 Critical severity
Firefox: NULL Pointer Dereference
`NSC_DeriveKey` inadvertently assumed that the `phKey` parameter is always non-NULL. When it was passed as NULL, a segmentation fault (SEGV) occurred, leading to crashes. This behavior conflicted with the PKCS#11 v3.0 specification, which allows `phKey` to be
- 9.8 Critical severity
Firefox: Double Free
A double-free issue could have occurred in `sec_pkcs7_decoder_start_decrypt()` when handling an error path. Under specific conditions, the same symmetric key could have been freed twice, potentially leading to memory corruption. This vulnerability affects Fire
- 7.5 High severity
Firefox: Inappropriate Encoding for Output Context
Copying sensitive information from Private Browsing tabs on Android, such as passwords, may have inadvertently stored data in the cloud-based clipboard history if enabled. This vulnerability affects Firefox < 133 and Thunderbird < 133.
- 8.1 High severity
Firefox: Improper Restriction of Rendered UI Layers or Frames
Malicious websites may have been able to perform user intent confirmation through tapjacking. This could have led to users unknowingly approving the launch of external applications, potentially exposing them to underlying vulnerabilities. This vulnerability af
- 8.8 High severity
Firefox: Improper Control of Generation of Code
Memory safety bugs present in Firefox 132, Firefox ESR 128.4, and Thunderbird 128.4. 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: Improper Control of Generation of Code
When handling keypress events, an attacker may have been able to trick a user into bypassing the "Open Executable File?" confirmation dialog. This could have led to malicious code execution. This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunde
- 8.8 High severity
Firefox: Out-of-bounds Write
Certain WebGL operations on Apple silicon M series devices could have lead to an out-of-bounds write and memory corruption due to a flaw in Apple's GPU driver. *This bug only affected the application on Apple M series hardware. Other platforms were unaffected.
- 7.8 High severity
sccache: Untrusted Search Path
On Linux the sccache client can execute arbitrary code with the privileges of a local sccache server, by preloading the code in a shared library passed to LD_PRELOAD. If the server is run as root (which is the default when installing the snap package https://s
- 8.4 High severity
Convict: Improperly Controlled Modification of Object Prototype Attributes
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') vulnerability in Mozilla Convict. This allows an attacker to inject attributes that are used in other components, or to override existing attributes with ones that have i
- 8.8 High severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 131, Firefox ESR 128.3, and Thunderbird 128.3. 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: Uncontrolled Resource Consumption
By sending a specially crafted push message, a remote server could have hung the parent process, causing the browser to become unresponsive. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.
- 7.5 High severity
Firefox: Use After Free
An attacker could have caused a use-after-free when accessibility was enabled, leading to a potentially exploitable crash. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Firefox ESR < 115.17, Thunderbird < 128.4, and Thunderbird < 132.
- 7.5 High severity
Firefox: Improper Preservation of Permissions
A permission leak could have occurred from a trusted site to an untrusted site via `embed` or `object` elements. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Firefox ESR < 115.17, Thunderbird < 128.4, and Thunderbird < 132.
- 9.1 Critical severity
Firefox for iOS: Improper Restriction of Rendered UI Layers or Frames
Opening an external link to an HTTP website when Firefox iOS was previously closed and had an HTTPS tab open could in some cases result in the padlock icon showing an HTTPS indicator incorrectly This vulnerability affects Firefox for iOS < 131.2.
- 9.8 Critical severity
Mozilla Firefox Use-After-Free Exploited
An attacker was able to achieve code execution in the content process by exploiting a use-after-free in Animation timelines. We have had reports of this vulnerability being exploited in the wild. This vulnerability affects Firefox < 131.0.2, Firefox ESR < 128.
- 7.3 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Memory safety bugs present in Firefox 130. 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 < 131 and Thunderbird <
- 9.8 Critical severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
Memory safety bugs present in Firefox 130, Firefox ESR 128.2, and Thunderbird 128.2. 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: Improper Restriction of Operations within the Bounds of a Memory Buffer
Memory safety bugs present in Firefox 130, Firefox ESR 115.15, Firefox ESR 128.2, and Thunderbird 128.2. 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 cod
- 8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
A potential memory corruption vulnerability could be triggered if an attacker had the ability to trigger an OOM at a specific moment during JIT compilation. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 1
- 7.5 High severity
Firefox: Improper Resource Shutdown or Release
A website configured to initiate a specially crafted WebTransport session could crash the Firefox process leading to a denial of service condition. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.
- 8.8 High severity
Firefox: Improper Restriction of Operations within the Bounds of a Memory Buffer
It is currently unknown if this issue is exploitable but a condition may arise where the structured clone of certain objects could lead to memory corruption. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird <
- 7.5 High severity
Firefox: Improper Neutralization of Input During Web Page Generation
An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the `resource://devtools` origin. This could allow them to access cross-origin JSON content. This access is limited to "same site" documents by the Site Isolation
- 7.5 High severity
Firefox: Origin Validation Error
An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the `resource://pdf.js` origin. This could allow them to access cross-origin PDF content. This access is limited to "same site" documents by the Site Isolation fe
- 9.8 Critical severity
Firefox: Origin Validation Error
A compromised content process could have allowed for the arbitrary loading of cross-origin pages. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Firefox ESR < 115.16, Thunderbird < 128.3, and Thunderbird < 131.
- 7.5 High severity
Firefox: Incorrect Permission Assignment for Critical Resource
An attacker could write data to the user's clipboard, bypassing the user prompt, during a certain sequence of navigational events. This vulnerability affects Firefox < 129, Firefox ESR < 128.3, and Thunderbird < 128.3.
- 7.5 High severity
Firefox: NULL Pointer Dereference
An error in the ECMA-262 specification relating to Async Generators could have resulted in a type confusion, potentially leading to memory corruption and an exploitable crash. This vulnerability affects Firefox < 128, Firefox ESR < 115.13, Thunderbird < 115.13
- 9.8 Critical severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 129. 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 < 130.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
Memory safety bugs present in Firefox 129, Firefox ESR 128.1, and Thunderbird 128.1. 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 vulnerabilit
- 9.8 Critical severity
Firefox: Access of Resource Using Incompatible Type
A difference in the handling of StructFields and ArrayTypes in WASM could be used to trigger an exploitable type confusion vulnerability. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Thunderbird < 128.2.
- 9.8 Critical severity
Firefox: Out-of-bounds Write
The JavaScript garbage collector could mis-color cross-compartment objects if OOM conditions were detected at the right point between two passes. This could have led to memory corruption. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, Firefox E
- 7.5 High severity
Firefox: Initialization of a Resource with an Insecure Default
Firefox normally asks for confirmation before asking the operating system to find an application to handle a scheme that the browser does not support. It did not ask before doing so for the Usenet-related schemes news: and snews:. Since most operating systems
- 8.8 High severity
Firefox: Improper Check for Dropped Privileges
Internal browser event interfaces were exposed to web content when privileged EventHandler listener callbacks ran for those events. Web content that tried to use those interfaces would not be able to use them with elevated privileges, but their presence would
- 9.8 Critical severity
Firefox: Access of Resource Using Incompatible Type
A potentially exploitable type confusion could be triggered when looking up a property name on an object being used as the `with` environment. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, Firefox ESR < 115.15, Thunderbird < 128.2, and Thunder
- 8.8 High severity
Firefox: Use After Free
Incorrect garbage collection interaction in IndexedDB could have led to a use-after-free. This vulnerability affects Firefox < 129, Firefox ESR < 128.1, and Thunderbird < 128.1.
- 8.8 High severity
Firefox: Use After Free
Unexpected marking work at the start of sweeping 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.