Mozilla Thunderbird vulnerabilities

CVE-2026-84142 [CRITICAL] CWE-119 CVE-2026-84142: Internally found bugs present in Thunderbird 154. Some of these bugs showed evidence of memory corru Internally found bugs present in Thunderbird 154. 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 and Thunderbird 155.

CVE-2025-14330 [CRITICAL] CWE-119 CVE-2025-14330: 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 146, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.

CVE-2026-0892 [CRITICAL] CWE-119 CVE-2026-0892: Memory safety bugs present in Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of Memory safety bugs present in Firefox 146 and Thunderbird 146. 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 147 and Thunderbird 147.

CVE-2026-2777 [CRITICAL] CWE-269 CVE-2026-2777: Privilege escalation in the Messaging System component. This vulnerability was fixed in Firefox 148, Privilege escalation in the Messaging System component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVE-2026-4729 [CRITICAL] CWE-120 CVE-2026-4729: Memory safety bugs present in Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of Memory safety bugs present in Firefox 148 and Thunderbird 148. 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 149 and Thunderbird 149.

CVE-2026-8401 [CRITICAL] Mozilla Foundation Security Advisory 2026-51: CVE-2026-8401 Mozilla Foundation Security Advisory 2026-51 CVE: CVE-2026-8401 Product: Thunderbird Impact: high Fixed in: Thunderbird 140.11

CVE-2026-12293 [CRITICAL] CWE-416 CVE-2026-12293: Use-after-free in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and Th Use-after-free in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

CVE-2026-2807 [CRITICAL] CWE-787 CVE-2026-2807: Memory safety bugs present in Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of Memory safety bugs present in Firefox 147 and Thunderbird 147. 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 148 and Thunderbird 148.

CVE-2026-5735 [CRITICAL] CWE-787 CVE-2026-5735: Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evi Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. 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 was fixed in Firefox 149.0.2 and Thunderbird 149.0.2.

CVE-2011-2378 [CRITICAL] CWE-94 CVE-2011-2378: The appendChild function in Mozilla Firefox before 3.6.20, Thunderbird 3.x before 3.1.12, SeaMonkey The appendChild function in Mozilla Firefox before 3.6.20, Thunderbird 3.x before 3.1.12, SeaMonkey 2.x, and possibly other products does not properly handle DOM objects, which allows remote attackers to execute arbitrary code via unspecified vectors that lead to dereferencing of a "dangling pointer."

CVE-2011-0085 [CRITICAL] CWE-399 CVE-2011-0085: Use-after-free vulnerability in the nsXULCommandDispatcher function in Mozilla Firefox before 3.6.18 Use-after-free vulnerability in the nsXULCommandDispatcher function in Mozilla Firefox before 3.6.18, Thunderbird before 3.1.11, and SeaMonkey through 2.0.14 allows remote attackers to execute arbitrary code via a crafted XUL document that dequeues the current command updater.

CVE-2026-16394 Mozilla Foundation Security Advisory 2026-71: CVE-2026-16394 Mozilla Foundation Security Advisory 2026-71 CVE: CVE-2026-16394 Product: Thunderbird Impact: high Fixed in: Thunderbird 153

CVE-2026-12296 [CRITICAL] CWE-693 CVE-2026-12296: Sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefo Sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

CVE-2026-12297 [CRITICAL] CWE-119 CVE-2026-12297: Sandbox escape due to incorrect boundary conditions in the Networking component. This vulnerability Sandbox escape due to incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

CVE-2013-5600 [CRITICAL] CVE-2013-5600: Use-after-free vulnerability in the nsIOService::NewChannelFromURIWithProxyFlags function in Mozilla Use-after-free vulnerability in the nsIOService::NewChannelFromURIWithProxyFlags function in Mozilla Firefox before 25.0, Firefox ESR 17.x before 17.0.10 and 24.x before 24.1, Thunderbird before 24.1, Thunderbird ESR 17.x before 17.0.10, and SeaMonkey before 2.22 allows remote attackers to execute arbitrary code via vectors involving a blob: URL.

CVE-2026-84121 [CRITICAL] CWE-416 CVE-2026-84121: Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

CVE-2013-5601 [CRITICAL] CVE-2013-5601: Use-after-free vulnerability in the nsEventListenerManager::SetEventHandler function in Mozilla Fire Use-after-free vulnerability in the nsEventListenerManager::SetEventHandler function in Mozilla Firefox before 25.0, Firefox ESR 17.x before 17.0.10 and 24.x before 24.1, Thunderbird before 24.1, Thunderbird ESR 17.x before 17.0.10, and SeaMonkey before 2.22 allows remote attackers to execute arbitrary code via vectors related to a memory allocation through

CVE-2026-100800 [CRITICAL] CWE-416 CVE-2026-100800: Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.

CVE-2012-5839 [CRITICAL] CWE-787 CVE-2012-5839: Heap-based buffer overflow in the gfxShapedWord::CompressedGlyph::IsClusterStart function in Mozilla Heap-based buffer overflow in the gfxShapedWord::CompressedGlyph::IsClusterStart 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 unspecified vectors.

CVE-2026-100828 [CRITICAL] CWE-693 CVE-2026-100828: Mitigation bypass in the Bookmarks & History component. This vulnerability was fixed in Firefox ESR Mitigation bypass in the Bookmarks & History component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.