Firefox / Thunderbird vulnerabilities
54 known CVE vulnerabilities in Firefox / Thunderbird, translated and rated.
- CVE-2026-16408Critical
Integer overflow in the Audio/Video: Playback component in Firefox and Thunderbird. Fixed in versions 153.
- CVE-2026-16395Critical
Integer overflow in the Audio/Video component in Firefox and Thunderbird. Fixed in versions 153.
- CVE-2026-6770Medium
A security issue exists in the Storage: IndexedDB component of the Firefox browser and the Thunderbird mail client. The vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- CVE-2026-4729Critical
Memory safety bugs were found in Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption, which could potentially allow arbitrary code execution. The vulnerabilities were fixed in Firefox 149 and Thunderbird 149.
- CVE-2026-4720Critical
Memory safety bugs were found in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and could potentially be exploited to run arbitrary code with enough effort.
- CVE-2026-2807Critical
Memory safety bugs were found in Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and could potentially be exploited to run arbitrary code. The vulnerability was fixed in Firefox 148 and Thunderbird 148.
- CVE-2026-2792Critical
Memory safety bugs were found in Firefox ESR 140.7, Firefox 147, Thunderbird ESR 140.7, and Thunderbird 147. Some of these bugs showed evidence of memory corruption and could potentially be exploited to run arbitrary code with enough effort.
- CVE-2026-118008High
Privilege escalation vulnerability in the DOM: Navigation component. It was fixed in Firefox 159 and Thunderbird 159.
- CVE-2026-117991Low risk· EPSS 8%
The vulnerability stems from incorrect boundary conditions in the Layout: Text and Fonts component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117990Low risk· EPSS 8%
The vulnerability allows a sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117989Low risk· EPSS 8%
A use-after-free vulnerability exists in the Graphics component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117988Low risk· EPSS 8%
The vulnerability allows a sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117987Low risk· EPSS 8%
A use-after-free vulnerability exists in the Graphics component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117986Low risk· EPSS 8%
A use-after-free vulnerability exists in the Graphics component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117985Low risk· EPSS 8%
The vulnerability allows a sandbox escape due to a use-after-free in the Graphics component. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117984Low risk· EPSS 8%
The vulnerability stems from incorrect boundary conditions in the Layout: Scrolling and Overflow component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117983Low risk· EPSS 8%
A use-after-free vulnerability exists in the Graphics component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117982Low risk· EPSS 8%
The vulnerability stems from an invalid pointer in the JavaScript Engine: JIT component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117915Low risk· EPSS 8%
Incorrect boundary conditions in the Layout: Block and Inline component of Firefox and Thunderbird. The vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117914Low risk· EPSS 8%
Use-after-free in the SVG component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117913Low risk· EPSS 8%
Use-after-free in the SVG component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117912Low risk· EPSS 9%
Same-origin policy bypass in the CSS Parsing and Computation component of Firefox and Thunderbird. The vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117911Low risk· EPSS 8%
Use-after-free in the Audio/Video: Playback component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117910Low risk· EPSS 8%
Invalid pointer in the JavaScript Engine component of Firefox and Thunderbird. The vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117909Low risk· EPSS 8%
Use-after-free in the JavaScript: GC component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117908Low risk· EPSS 8%
Use-after-free in the Graphics: ImageLib component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117907Low risk· EPSS 8%
Use-after-free in the Networking component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-117906Low risk· EPSS 8%
Use-after-free in the CSS Parsing and Computation component of Firefox and Thunderbird. It was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-109781Medium
Denial-of-service in the Printing: Output component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
- CVE-2026-109779Medium
Race condition in the Networking: DNS component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
- CVE-2026-100801High
Privilege escalation vulnerability in the DLL Services component. It was fixed in multiple Firefox and Thunderbird versions, including Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- CVE-2026-74978High
Clickjacking vulnerability in the Widget component in Firefox and Thunderbird. The issue was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
- CVE-2026-74977High
Integer overflow in the Graphics component in Firefox and Thunderbird. The issue was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
- CVE-2026-74965High
Privilege escalation in the Shell Integration component in Firefox and Thunderbird. The issue was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
- CVE-2026-74958High
Information disclosure in the WebRTC component in Firefox and Thunderbird. The issue was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
- CVE-2026-74955High
Privilege escalation in the Request Handling component in Firefox and Thunderbird. The issue was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
- CVE-2026-12326High
Memory safety bugs were found in Firefox 151 and Thunderbird 151. Some of these bugs showed evidence of memory corruption, potentially allowing arbitrary code execution. The vulnerabilities were fixed in Firefox 152 and Thunderbird 152.
- CVE-2026-8971Medium
A same-origin policy bypass exists in the Networking: JAR component of Firefox and Thunderbird. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
- CVE-2026-8964High
Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
- CVE-2026-6783Medium
Incorrect boundary conditions and integer overflow exist in the Audio/Video: Playback component of Firefox and Thunderbird. The vulnerability was fixed in Firefox 150 and Thunderbird 150.
- CVE-2026-6774Medium
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.
- CVE-2026-6764Medium
Incorrect boundary conditions exist in the DOM: Device Interfaces component of Firefox and Thunderbird. The issue was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- CVE-2026-6762Medium
A spoofing issue exists in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- CVE-2025-11716Medium
Links in a sandboxed iframe could open an external app on Android without the required "allow-" permission. The vulnerability was fixed in Firefox 144 and Thunderbird 144.
- CVE-2025-11711Medium
There was a way to change the value of JavaScript object properties that were supposed to be non-writeable. This vulnerability was fixed in Firefox 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.
- CVE-2025-10531Medium
A mitigation bypass exists in the Web Compatibility: Tooling component. The vulnerability was fixed in Firefox 143 and Thunderbird 143.
- CVE-2025-4092Medium
Memory safety bugs present in Firefox 137 and Thunderbird 137. 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 138 and Thunderbird 138.
- CVE-2025-3028Medium
JavaScript code running while transforming a document with the XSLTProcessor could lead to a use-after-free. This vulnerability was fixed in Firefox 137, Firefox ESR 115.22, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9.
- CVE-2025-0239Medium
When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.
- CVE-2025-0238Medium
Assuming a controlled failed memory allocation, an attacker could have caused a use-after-free, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Firefox ESR 115.19, Thunderbird 134, and Thunderbird 128.6.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

