Mozilla FireFox Extended Support Release (ESR)

Thunderbird's update mechanism

CVE-2025-2817 - April 29, 2025

Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.

An attacker was able to achieve code execution in the content process by exploiting a use-after-free in Animation timelines

CVE-2024-9680 9.8 - Critical - October 09, 2024

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 < 128.3.1, Firefox ESR < 115.16.1, Thunderbird < 131.0.1, Thunderbird < 128.3.1, and Thunderbird < 115.16.0.

Dangling pointer

By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements

CVE-2024-9398 5.3 - Medium - October 01, 2024

By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements that protocol handler is installed. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.

A missing delay in directory upload UI could have made it possible for an attacker to trick a user into granting permission

CVE-2024-9397 6.1 - Medium - October 01, 2024

A missing delay in directory upload UI could have made it possible for an attacker to trick a user into granting permission via clickjacking. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.

Clickjacking

An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the `resource://devtools` origin

CVE-2024-9394 7.5 - High - October 01, 2024

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 feature on desktop clients, but full cross-origin access is possible on Android versions. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Firefox ESR < 115.16, Thunderbird < 128.3, and Thunderbird < 131.

An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the `resource://pdf.js` origin

CVE-2024-9393 7.5 - High - October 01, 2024

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 feature on desktop clients, but full cross-origin access is possible on Android versions. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Firefox ESR < 115.16, Thunderbird < 128.3, and Thunderbird < 131.

Memory safety bugs present in Firefox 129, Firefox ESR 128.1, and Thunderbird 128.1

CVE-2024-8387 9.8 - Critical - September 03, 2024

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 vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Thunderbird < 128.2.

Memory Corruption

If a site had been granted the permission to open popup windows

CVE-2024-8386 6.1 - Medium - September 03, 2024

If a site had been granted the permission to open popup windows, it could cause Select elements to appear on top of another site to perform a spoofing attack. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Thunderbird < 128.2.

Open Redirect

A difference in the handling of StructFields and ArrayTypes in WASM could be used to trigger an exploitable type confusion vulnerability

CVE-2024-8385 9.8 - Critical - September 03, 2024

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.

Object Type Confusion

The JavaScript garbage collector could mis-color cross-compartment objects if OOM conditions were detected at the right point between two passes

CVE-2024-8384 9.8 - Critical - September 03, 2024

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 ESR < 115.15, Thunderbird < 128.2, and Thunderbird < 115.15.

Memory Corruption

Firefox normally asks for confirmation before asking the operating system to find an application to handle a scheme

CVE-2024-8383 7.5 - High - September 03, 2024

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 don't have a trusted newsreader installed by default, an unscrupulous program that the user downloaded could register itself as a handler. The website that served the application download could then launch that application at will. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Firefox ESR < 115.15.

Internal browser event interfaces were exposed to web content when privileged EventHandler listener callbacks ran for those events

CVE-2024-8382 8.8 - High - September 03, 2024

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 indicate certain browser features had been used, such as when a user opened the Dev Tools console. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, Firefox ESR < 115.15, Thunderbird < 128.2, and Thunderbird < 115.15.

A potentially exploitable type confusion could be triggered when looking up a property name on an object being used as the `with` environment

CVE-2024-8381 9.8 - Critical - September 03, 2024

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 Thunderbird < 115.15.

Object Type Confusion

Calling `PK11_Encrypt()` in NSS using CKM_CHACHA20 and the same buffer for input and output

CVE-2024-7531 6.5 - Medium - August 06, 2024

Calling `PK11_Encrypt()` in NSS using CKM_CHACHA20 and the same buffer for input and output can result in plaintext on an Intel Sandy Bridge processor. In Firefox this only affects the QUIC header protection feature when the connection is using the ChaCha20-Poly1305 cipher suite. The most likely outcome is connection failure, but if the connection persists despite the high packet loss it could be possible for a network observer to identify packets as coming from the same source despite a network path change. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, and Firefox ESR < 128.1.

The date picker could partially obscure security prompts

CVE-2024-7529 6.5 - Medium - August 06, 2024

The date picker could partially obscure security prompts. This could be used by a malicious site to trick a user into granting permissions. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

Incorrect garbage collection interaction in IndexedDB could have led to a use-after-free

CVE-2024-7528 8.8 - High - August 06, 2024

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.

Dangling pointer

Unexpected marking work at the start of sweeping could have led to a use-after-free

CVE-2024-7527 8.8 - High - August 06, 2024

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.

Dangling pointer

ANGLE failed to initialize parameters which lead to reading from uninitialized memory

CVE-2024-7526 6.5 - Medium - August 06, 2024

ANGLE failed to initialize parameters which lead to reading from uninitialized memory. This could be leveraged to leak sensitive data from memory. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

Use of Uninitialized Resource

It was possible for a web extension with minimal permissions to create a `StreamFilter`

CVE-2024-7525 8.1 - High - August 06, 2024

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, Thunderbird < 128.1, and Thunderbird < 115.14.

Incorrect Default Permissions

Editor code failed to check an attribute value

CVE-2024-7522 8.8 - High - August 06, 2024

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.

Out-of-bounds Read

Incomplete WebAssembly exception handing could have led to a use-after-free

CVE-2024-7521 8.8 - High - August 06, 2024

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.

Improper Handling of Exceptional Conditions

A type confusion bug in WebAssembly could be leveraged by an attacker to potentially achieve code execution

CVE-2024-7520 8.8 - High - August 06, 2024

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.

Object Type Confusion

Insufficient checks when processing graphics shared memory could have led to memory corruption

CVE-2024-7519 9.6 - Critical - August 06, 2024

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 < 128.1, and Thunderbird < 115.14.

Memory Corruption

Select options could obscure the fullscreen notification dialog

CVE-2024-7518 6.5 - Medium - August 06, 2024

Select options could obscure the fullscreen notification dialog. This could be used by a malicious site to perform a spoofing attack. This vulnerability affects Firefox < 129, Firefox ESR < 128.1, and Thunderbird < 128.1.

Firefox adds web-compatibility shims in place of some tracking scripts blocked by Enhanced Tracking Protection

CVE-2024-7524 6.1 - Medium - August 06, 2024

Firefox adds web-compatibility shims in place of some tracking scripts blocked by Enhanced Tracking Protection. On a site protected by Content Security Policy in "strict-dynamic" mode, an attacker able to inject an HTML element could have used a DOM Clobbering attack on some of the shims and achieved XSS, bypassing the CSP strict-dynamic protection. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, and Firefox ESR < 128.1.

XSS

By monitoring the time certain operations take, an attacker could have guessed

CVE-2024-5690 4.3 - Medium - June 11, 2024

By monitoring the time certain operations take, an attacker could have guessed which external protocol handlers were functional on a user's system. This vulnerability affects Firefox < 127, Firefox ESR < 115.12, and Thunderbird < 115.12.

Side Channel Attack

By tricking the browser with a `X-Frame-Options` header, a sandboxed iframe could have presented a button

CVE-2024-5691 4.7 - Medium - June 11, 2024

By tricking the browser with a `X-Frame-Options` header, a sandboxed iframe could have presented a button that, if clicked by a user, would bypass restrictions to open a new window. This vulnerability affects Firefox < 127, Firefox ESR < 115.12, and Thunderbird < 115.12.

It was possible for certain browser prompts and dialogs to be activated or dismissed unintentionally by the user due to an incorrect timestamp used to prevent input after page load

CVE-2024-0742 4.3 - Medium - January 23, 2024

It was possible for certain browser prompts and dialogs to be activated or dismissed unintentionally by the user due to an incorrect timestamp used to prevent input after page load. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

Memory safety bugs present in Firefox 121, Firefox ESR 115.6, and Thunderbird 115.6

CVE-2024-0755 8.8 - High - January 23, 2024

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 vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

An out of bounds write in ANGLE could have allowed an attacker to corrupt memory leading to a potentially exploitable crash

CVE-2024-0741 6.5 - Medium - January 23, 2024

An out of bounds write in ANGLE could have allowed an attacker to corrupt memory leading to a potentially exploitable crash. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

Memory Corruption

In specific HSTS configurations an attacker could have bypassed HSTS on a subdomain

CVE-2024-0753 6.5 - Medium - January 23, 2024

In specific HSTS configurations an attacker could have bypassed HSTS on a subdomain. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

A malicious devtools extension could have been used to escalate privileges

CVE-2024-0751 8.8 - High - January 23, 2024

A malicious devtools extension could have been used to escalate privileges. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

Improper Privilege Management

A bug in popup notifications delay calculation could have made it possible for an attacker to trick a user into granting permissions

CVE-2024-0750 8.8 - High - January 23, 2024

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.

A phishing site could have repurposed an `about:` dialog to show phishing content with an incorrect origin in the address bar

CVE-2024-0749 4.3 - Medium - January 23, 2024

A phishing site could have repurposed an `about:` dialog to show phishing content with an incorrect origin in the address bar. This vulnerability affects Firefox < 122 and Thunderbird < 115.7.

Origin Validation Error

When a parent page loaded a child in an iframe with `unsafe-inline`

CVE-2024-0747 6.5 - Medium - January 23, 2024

When a parent page loaded a child in an iframe with `unsafe-inline`, the parent Content Security Policy could have overridden the child Content Security Policy. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

A Linux user opening the print preview dialog could have caused the browser to crash

CVE-2024-0746 6.5 - Medium - January 23, 2024

A Linux user opening the print preview dialog could have caused the browser to crash. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

A use-after-free condition affected TLS socket creation when under memory pressure

CVE-2023-6859 8.8 - High - December 19, 2023

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.

Dangling pointer

The WebGL `DrawElementsInstanced` method was susceptible to a heap buffer overflow when used on systems with the Mesa VM driver

CVE-2023-6856 8.8 - High - December 19, 2023

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 < 115.6, Thunderbird < 115.6, and Firefox < 121.

Memory Corruption

The timing of a button click causing a popup to disappear was approximately the same length as the anti-clickjacking delay on permission prompts

CVE-2023-6867 6.1 - Medium - December 19, 2023

The timing of a button click causing a popup to disappear was approximately the same length as the anti-clickjacking delay on permission prompts. It was possible to use this fact to surprise users by luring them to click where the permission grant button would be about to appear. This vulnerability affects Firefox ESR < 115.6 and Firefox < 121.

Clickjacking

`EncryptingOutputStream` was susceptible to exposing uninitialized data

CVE-2023-6865 6.5 - Medium - December 19, 2023

`EncryptingOutputStream` was susceptible to exposing uninitialized data. This issue could only be abused in order to write data to a local disk which may have implications for private browsing mode. This vulnerability affects Firefox ESR < 115.6 and Firefox < 121.

Memory safety bugs present in Firefox 120, Firefox ESR 115.5, and Thunderbird 115.5

CVE-2023-6864 8.8 - High - December 19, 2023

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 vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.

Memory Corruption

The `ShutdownObserver()` was susceptible to potentially undefined behavior due to its reliance on a dynamic type

CVE-2023-6863 8.8 - High - December 19, 2023

The `ShutdownObserver()` was susceptible to potentially undefined behavior due to its reliance on a dynamic type that lacked a virtual destructor. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.

A use-after-free was identified in the `nsDNSService::Init`

CVE-2023-6862 8.8 - High - December 19, 2023

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.

Dangling pointer

The `nsWindow::PickerOpen(void)` method was susceptible to a heap buffer overflow when running in headless mode

CVE-2023-6861 8.8 - High - December 19, 2023

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.

Memory Corruption

Firefox was susceptible to a heap buffer overflow in `nsTextFragment` due to insufficient OOM handling

CVE-2023-6858 8.8 - High - December 19, 2023

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.

Memory Corruption

The `VideoBridge` allowed any content process to use textures produced by remote decoders

CVE-2023-6860 6.5 - Medium - December 19, 2023

The `VideoBridge` allowed any content process to use textures produced by remote decoders. This could be abused to escape the sandbox. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.

Memory safety bugs present in Firefox 119, Firefox ESR 115.4, and Thunderbird 115.4

CVE-2023-6212 8.8 - High - November 21, 2023

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 vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.

Memory Corruption

Ownership mismanagement led to a use-after-free in ReadableByteStreams This vulnerability affects Firefox < 120

CVE-2023-6207 8.8 - High - November 21, 2023

Ownership mismanagement led to a use-after-free in ReadableByteStreams This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.

Dangling pointer

On some systemsdepending on the graphics settings and driversit was possible to force an out-of-bounds read and leak memory data into the images created on the

CVE-2023-6204 6.5 - Medium - November 21, 2023

On some systemsdepending on the graphics settings and driversit was possible to force an out-of-bounds read and leak memory data into the images created on the canvas element. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.

Out-of-bounds Read

When using X11

CVE-2023-6208 8.8 - High - November 21, 2023

When using X11, text selected by the page using the Selection API was erroneously copied into the primary selection, a temporary storage not unlike the clipboard. *This bug only affects Firefox on X11. Other systems are unaffected.* This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.