Mozilla Firefox vulnerabilities

CVE-2026-84143 [CRITICAL] CWE-119 CVE-2026-84143: Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 140.14. Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 140.14. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155, Firefox ESR 140.15, Firefox ESR 1

CVE-2026-106016 [CRITICAL] CWE-693 CVE-2026-106016: Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 157.0.1 an Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 157.0.1 and Thunderbird 158.

CVE-2026-2790 [CRITICAL] CWE-346 CVE-2026-2790: Same-origin policy bypass in the Networking: JAR component. This vulnerability was fixed in Firefox Same-origin policy bypass in the Networking: JAR component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-74959 [CRITICAL] CWE-693 CVE-2026-74959: Mitigation bypass in the Storage: Cache API component. This vulnerability was fixed in Firefox 154, Mitigation bypass in the Storage: Cache API component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

CVE-2026-16359 [CRITICAL] CWE-119 CVE-2026-16359: Incorrect boundary conditions in the Audio/Video: GMP component. This vulnerability was fixed in Fir Incorrect boundary conditions in the Audio/Video: GMP component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

CVE-2026-92075 [CRITICAL] CWE-693 CVE-2026-92075: Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 156, Firefox Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.

CVE-2026-92041 [CRITICAL] CWE-693 CVE-2026-92041: Mitigation bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 156, Fir Mitigation bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.

CVE-2026-92057 [CRITICAL] CWE-693 CVE-2026-92057: Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 156, Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.

CVE-2026-12315 [CRITICAL] CWE-693 CVE-2026-12315: Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152, Firef Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

CVE-2026-12316 [CRITICAL] CWE-693 CVE-2026-12316: Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152 and Th Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

CVE-2026-12304 [CRITICAL] CWE-346 CVE-2026-12304: Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Fire Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

CVE-2013-5618 [CRITICAL] CWE-416 CVE-2013-5618: Use-after-free vulnerability in the nsNodeUtils::LastRelease function in the table-editing user inte Use-after-free vulnerability in the nsNodeUtils::LastRelease function in the table-editing user interface in the editor component in Mozilla Firefox before 26.0, Firefox ESR 24.x before 24.2, Thunderbird before 24.2, and SeaMonkey before 2.23 allows remote attackers to execute arbitrary code by triggering improper garbage collection.

CVE-2012-4202 [CRITICAL] CWE-787 CVE-2012-4202: Heap-based buffer overflow in the image::RasterImage::DrawFrameTo function in Mozilla Firefox before Heap-based buffer overflow in the image::RasterImage::DrawFrameTo function in Mozilla Firefox before 17.0, Firefox ESR 10.x before 10.0.11, Thunderbird before 17.0, Thunderbird ESR 10.x before 10.0.11, and SeaMonkey before 2.14 allows remote attackers to execute arbitrary code via a crafted GIF image.

CVE-2012-3957 [CRITICAL] CWE-787 CVE-2012-3957: Heap-based buffer overflow in the nsBlockFrame::MarkLineDirty function in Mozilla Firefox before 15. Heap-based buffer overflow in the nsBlockFrame::MarkLineDirty function in Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey before 2.12 allows remote attackers to execute arbitrary code via unspecified vectors.

CVE-2020-12389 [CRITICAL] CWE-20 CVE-2020-12389: The Firefox content processes did not sufficiently lockdown access control which could result in a s The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape. *Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects Firefox ESR < 68.8 and Firefox < 76.

CVE-2019-9794 [CRITICAL] CWE-88 CVE-2019-9794: A vulnerability was discovered where specific command line arguments are not properly discarded duri A vulnerability was discovered where specific command line arguments are not properly discarded during Firefox invocation as a shell handler for URLs. This could be used to retrieve and execute files whose location is supplied through these command line arguments if Firefox is configured as the default URI handler for a given URI scheme in third part

CVE-2020-6823 [CRITICAL] CWE-862 CVE-2020-6823: A malicious extension could have called <code>browser.identity.launchWebAuthFlow</code>, controlling A malicious extension could have called browser.identity.launchWebAuthFlow, controlling the redirect_uri, and through the Promise returned, obtain the Auth code and gain access to the user's account at the service provider. This vulnerability affects Firefox < 75.

CVE-2009-1839 [MEDIUM] CWE-264 CVE-2009-1839: Mozilla Firefox 3 before 3.0.11 associates an incorrect principal with a file: URL loaded through th Mozilla Firefox 3 before 3.0.11 associates an incorrect principal with a file: URL loaded through the location bar, which allows user-assisted remote attackers to bypass intended access restrictions and read files via a crafted HTML document, aka a "file-URL-to-file-URL scripting" attack.

CVE-2026-2773 [CRITICAL] CWE-119 CVE-2026-2773: Incorrect boundary conditions in the Web Audio component. This vulnerability was fixed in Firefox 14 Incorrect boundary conditions in the Web Audio component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-4698 [CRITICAL] CWE-843 CVE-2026-4698: JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.