Mozilla Thunderbird vulnerabilities

CVE-2026-2784 [CRITICAL] CWE-288 CVE-2026-2784: Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 148, Firef Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-6771 [CRITICAL] CWE-288 CVE-2026-6771: Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firef Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVE-2010-3769 [CRITICAL] CWE-119 CVE-2010-3769: The line-breaking implementation in Mozilla Firefox before 3.5.16 and 3.6.x before 3.6.13, Thunderbi The line-breaking implementation in Mozilla Firefox before 3.5.16 and 3.6.x before 3.6.13, Thunderbird before 3.0.11 and 3.1.x before 3.1.7, and SeaMonkey before 2.0.11 on Windows does not properly handle long strings, which allows remote attackers to execute arbitrary code via a crafted document.write call that triggers a buffer over-read.

CVE-2016-6354 [CRITICAL] CWE-119 CVE-2016-6354: Heap-based buffer overflow in the yy_get_next_buffer function in Flex before 2.6.1 might allow conte Heap-based buffer overflow in the yy_get_next_buffer function in Flex before 2.6.1 might allow context-dependent attackers to cause a denial of service or possibly execute arbitrary code via vectors involving num_to_read.

CVE-2022-24713 [HIGH] CVE-2022-24713: regex is an implementation of regular expressions for the Rust language regex is an implementation of regular expressions for the Rust language. The regex crate features built-in mitigations to prevent denial of service attacks caused by untrusted regexes, or untrusted input matched by trusted regexes. Those (tunable) mitigations already provide sane defaults to prevent attacks. This guarantee is documented and it's considered part of the crate's API. Unfort

CVE-2021-4140 [CRITICAL] CWE-91 CVE-2021-4140: It was possible to construct specific XSLT markup that would be able to bypass an iframe sandbox. Th It was possible to construct specific XSLT markup that would be able to bypass an iframe sandbox. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.

CVE-2026-4689 [CRITICAL] CWE-190 CVE-2026-4689: Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This v Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVE-2023-29542 [CRITICAL] CVE-2023-29542: A newline in a filename could have been used to bypass the file extension security mechanisms that r A newline in a filename could have been used to bypass the file extension security mechanisms that replace malicious file extensions such as .lnk with .download. This could have led to accidental execution of malicious code. *This bug only affects Firefox and Thunderbird on Windows. Other versions of Firefox and Thunderbird are unaffected.* This vulnerab

CVE-2020-6811 [HIGH] CWE-77 CVE-2020-6811: The 'Copy as cURL' feature of Devtools' network tab did not properly escape the HTTP method of a req The 'Copy as cURL' feature of Devtools' network tab did not properly escape the HTTP method of a request, which can be controlled by the website. If a user used the 'Copy as Curl' feature and pasted the command into a terminal, it could have resulted in command injection and arbitrary command execution. This vulnerability affects Thunderbird < 68.6, Fire

CVE-2026-2763 [CRITICAL] CWE-416 CVE-2026-2763: Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Fire Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-2764 [CRITICAL] CWE-416 CVE-2026-2764: JIT miscompilation, use-after-free in the JavaScript Engine: JIT component. This vulnerability was f JIT miscompilation, use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-2766 [CRITICAL] CWE-416 CVE-2026-2766: Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-2765 [CRITICAL] CWE-416 CVE-2026-2765: Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Fire Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-4702 [CRITICAL] CVE-2026-4702: JIT miscompilation in the JavaScript Engine component JIT miscompilation in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.

CVE-2026-2779 [CRITICAL] CWE-119 CVE-2026-2779: Incorrect boundary conditions in the Networking: JAR component. This vulnerability was fixed in Fire Incorrect boundary conditions in the Networking: JAR component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-2788 [CRITICAL] CWE-119 CVE-2026-2788: 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 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-16363 [CRITICAL] CWE-682 CVE-2026-16363: JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

CVE-2026-74940 [CRITICAL] CWE-416 CVE-2026-74940: Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

CVE-2026-2791 [CRITICAL] CWE-288 CVE-2026-2791: Mitigation bypass in the Networking: Cache component. This vulnerability was fixed in Firefox 148, F Mitigation bypass in the Networking: Cache component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-16357 [CRITICAL] CWE-119 CVE-2026-16357: Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 153 Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.