firefox vulnerabilities and fixes

Recent CVEs affecting firefox, with upgrade or downgrade steps. 51 tracked.

firefox has 51 tracked vulnerabilities, 8 critical. A fixed release or vendor patch exists for 51. Most recent: 2026-04-07. Highest priority: CVE-2025-6424 (score 65/100).

• CVE-2023-4050 HIGH 7.5 UPGRADE MITIGATE In some cases, an untrusted input stream was copied to a stack buffer without checking its size
• CVE-2023-29542 CRITICAL 9.8 UPGRADE UPGRADE A newline in a filename could have been used to bypass the file extension security mechanisms that replace mal
• CVE-2025-11708 CRITICAL 9.8 UPGRADE UPGRADE Use-after-free in MediaTrackGraphImpl::GetInstance()
• CVE-2026-5734 CRITICAL 9.8 UPGRADE UPGRADE Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 14
• CVE-2026-5735 CRITICAL 9.8 UPGRADE UPGRADE Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1
• CVE-2023-32214 HIGH 7.5 UPGRADE UPGRADE Protocol handlers `ms-cxh` and `ms-cxh-full` could have been leveraged to trigger a denial of service. *Note:
• CVE-2023-25744 HIGH 8.8 UPGRADE UPGRADE Mmemory safety bugs present in Firefox 109 and Firefox ESR 102.7
• CVE-2023-28162 HIGH 8.8 UPGRADE UPGRADE While implementing AudioWorklets, some code may have casted one type to another, invalid, dynamic type
• CVE-2023-29536 HIGH 8.8 UPGRADE UPGRADE An attacker could cause the memory manager to incorrectly free a pointer that addresses attacker-controlled me
• CVE-2023-29539 HIGH 8.8 UPGRADE UPGRADE When handling the filename directive in the Content-Disposition header, the filename would be truncated if the
• CVE-2023-32207 HIGH 8.8 UPGRADE UPGRADE A missing delay in popup notifications could have made it possible for an attacker to trick a user into granti
• CVE-2023-32213 HIGH 8.8 UPGRADE UPGRADE When reading a file, an uninitialized value could have been used as read limit
• CVE-2023-3600 HIGH 8.8 UPGRADE UPGRADE During the worker lifecycle, a use-after-free condition could have occurred, which could have led to a potenti
• CVE-2023-4049 MEDIUM 5.9 UPGRADE MITIGATE Race conditions in reference counting code were found through code inspection
• CVE-2023-37207 MEDIUM 6.5 UPGRADE UPGRADE A website could have obscured the fullscreen notification by using a URL with a scheme handled by an external
• CVE-2023-28163 MEDIUM 6.5 UPGRADE UPGRADE When downloading files through the Save As dialog on Windows with suggested filenames containing environment v
• CVE-2025-11715 HIGH 8.8 UPGRADE UPGRADE Memory safety bugs present in Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143
• CVE-2023-25751 MEDIUM 6.5 UPGRADE UPGRADE Sometimes, when invalidating JIT code while following an iterator, the newly generated code could be overwritt
• CVE-2023-32211 MEDIUM 6.5 UPGRADE UPGRADE A type checking bug would have led to invalid code being compiled
• CVE-2023-4052 MEDIUM 6.5 UPGRADE UPGRADE The Firefox updater created a directory writable by non-privileged users
• CVE-2023-23598 MEDIUM 6.5 UPGRADE UPGRADE Due to the Firefox GTK wrapper code's use of text/plain for drag data and GTK treating all text/plain MIMEs co
• CVE-2023-25738 MEDIUM 6.5 UPGRADE UPGRADE Members of the <code>DEVMODEW</code> struct set by the printer device driver weren't being validated and could
• CVE-2025-10532 MEDIUM 6.5 UPGRADE UPGRADE Incorrect boundary conditions in the JavaScript: GC component
• CVE-2025-11713 HIGH 8.1 UPGRADE UPGRADE Insufficient escaping in the “Copy as cURL” feature could have been used to trick a user into executing unexpe
• CVE-2023-23601 MEDIUM 6.5 UPGRADE UPGRADE Navigations were being allowed when dragging a URL from a cross-origin iframe into the same tab which could le
• CVE-2023-29532 MEDIUM 5.5 UPGRADE UPGRADE A local attacker can trick the Mozilla Maintenance Service into applying an unsigned update file by pointing t
• CVE-2025-6424 CRITICAL 9.8 UPGRADE A use-after-free in FontFaceSet resulted in a potentially exploitable crash
• CVE-2025-49710 CRITICAL 9.8 UPGRADE An integer overflow was present in `OrderedHashTable` used by the JavaScript engine
• CVE-2025-11709 CRITICAL 9.8 UPGRADE UPGRADE A compromised web process was able to trigger out of bounds reads and writes in a more privileged process usin
• CVE-2025-11710 CRITICAL 9.8 UPGRADE UPGRADE A compromised web process using malicious IPC messages could have caused the privileged browser process to rev
• CVE-2025-10533 HIGH 8.8 UPGRADE UPGRADE Integer overflow in the SVG component
• CVE-2025-10528 HIGH 7.3 UPGRADE UPGRADE Sandbox escape due to undefined behavior, invalid pointer in the Graphics: Canvas2D component
• CVE-2025-10537 HIGH 8.8 UPGRADE UPGRADE Memory safety bugs present in Firefox ESR 140.2, Thunderbird ESR 140.2, Firefox 142 and Thunderbird 142
• CVE-2025-11714 HIGH 8.8 UPGRADE UPGRADE Memory safety bugs present in Firefox ESR 115.28, Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Th
• CVE-2025-13014 HIGH 8.8 UPGRADE Use-after-free in the Audio/Video component
• CVE-2025-13020 HIGH 8.8 UPGRADE Use-after-free in the WebRTC: Audio/Video component
• CVE-2025-13016 HIGH 7.5 UPGRADE Incorrect boundary conditions in the JavaScript: WebAssembly component
• CVE-2025-6426 HIGH 8.8 UPGRADE The executable file warning did not warn users before opening files with the `terminal` extension
• CVE-2025-10529 MEDIUM 6.5 UPGRADE UPGRADE Same-origin policy bypass in the Layout component
• CVE-2025-13017 HIGH 8.1 UPGRADE Same-origin policy bypass in the DOM: Notifications component
• CVE-2025-13018 HIGH 8.1 UPGRADE Mitigation bypass in the DOM: Security component
• CVE-2025-13019 HIGH 8.1 UPGRADE Same-origin policy bypass in the DOM: Workers component
• CVE-2025-10527 HIGH 7.1 UPGRADE UPGRADE Sandbox escape due to use-after-free in the Graphics: Canvas2D component
• CVE-2025-13012 HIGH 7.5 UPGRADE Race condition in the Graphics component
• CVE-2025-6430 MEDIUM 6.1 UPGRADE When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the
• CVE-2025-11711 MEDIUM 6.5 UPGRADE UPGRADE There was a way to change the value of JavaScript Object properties that were supposed to be non-writeable
• CVE-2025-11712 MEDIUM 6.1 UPGRADE UPGRADE A malicious page could have used the type attribute of an OBJECT tag to override the default browser behavior
• CVE-2025-13013 MEDIUM 6.1 UPGRADE Mitigation bypass in the DOM: Core & HTML component
• CVE-2025-10536 MEDIUM 6.2 UPGRADE UPGRADE Information disclosure in the Networking: Cache component
• CVE-2025-6425 MEDIUM 4.3 UPGRADE An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that i
• CVE-2025-13015 LOW 3.4 UPGRADE Spoofing issue in Firefox

FAQ

How do I fix firefox vulnerabilities?

Open the CVE for your version, check the affected range, then follow the listed action: upgrade to the fixed release, or downgrade or mitigate if no fix exists yet. Commands for each OS are shown on every CVE page.

Is firefox being exploited right now?

None of the tracked firefox CVEs are on the CISA Known Exploited Vulnerabilities list at the moment. This is checked every 20 minutes.

Which firefox CVE should I patch first?

CVE-2025-6424 currently ranks highest (65/100): A use-after-free in FontFaceSet resulted in a potentially exploitable crash.

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