Mozilla Firefox (en-US) 151.0
Mozilla Firefox (en-US) 151.0, released May 19, 2026, fixes 31 CVEs in Mozilla Firefox (en-US). None of them is reported as exploited. Patch Radar priority: Urgent. The latest Mozilla Firefox (en-US) is 159.0, which also fixes every one of these CVEs.
Superseded. The latest Mozilla Firefox (en-US) is 159.0, which also fixes every CVE on this page. Install that instead.
Priority of the 31 CVEs
Applies to
| Product | Version |
|---|---|
| Mozilla Firefox (en-US) | 151.0 |
CVEs this fix closes
| Priority | CVE | Title | CVSS | EPSS | Exploitation |
|---|---|---|---|---|---|
| Urgent | CVE-2026-8948 | Same-origin policy bypass in the DOM: Networking component | 9.1 | 0.0042 | None reported |
| High | CVE-2026-8956 | Integer overflow in the Networking: JAR component | 9.8 | 0.0061 | None reported |
| High | CVE-2026-8949 | Integer overflow in the Widget: Win32 component | 7.5 | 0.0058 | None reported |
| High | CVE-2026-8946 | Incorrect boundary conditions in the Audio/Video: Web Codecs component | 7.5 | 0.0056 | None reported |
| High | CVE-2026-8953 | Sandbox escape due to use-after-free in the Disability Access APIs component | 9.6 | 0.0053 | None reported |
| High | CVE-2026-8975 | Memory safety bugs fixed in Thunderbird 140.11 and Thunderbird 151 | 8.8 | 0.0047 | None reported |
| High | CVE-2026-8954 | Incorrect boundary conditions, integer overflow in the Audio/Video component | 7.5 | 0.0043 | None reported |
| High | CVE-2026-8959 | Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component | 9.6 | 0.0042 | None reported |
| High | CVE-2026-8947 | Use-after-free in the DOM: Bindings (WebIDL) component | 7.5 | 0.0041 | None reported |
| High | CVE-2026-8968 | Denial-of-service due to invalid pointer in the Audio/Video: Web Codecs component | 7.5 | 0.0041 | None reported |
| High | CVE-2026-8955 | Privilege escalation in the DOM: Workers component | 8.8 | 0.0039 | None reported |
| High | CVE-2026-8957 | Privilege escalation in the Enterprise Policies component | 8.8 | 0.0039 | None reported |
| High | CVE-2026-8960 | Spoofing issue in WebExtensions | 7.5 | 0.0038 | None reported |
| High | CVE-2026-8952 | Privilege escalation in the Application Update component | 8.8 | 0.0037 | None reported |
| High | CVE-2026-8962 | Mitigation bypass in the DOM: Security component | 8.1 | 0.0037 | None reported |
| High | CVE-2026-8945 | Sandbox escape in Firefox and Firefox Focus for Android | 7.5 | 0.0037 | None reported |
| High | CVE-2026-8973 | Memory safety bugs fixed in Thunderbird 151 | 8.8 | 0.0037 | None reported |
| High | CVE-2026-8974 | Memory safety bugs fixed in Thunderbird 140.11 and Thunderbird 151 | 8.8 | 0.0037 | None reported |
| High | CVE-2026-8958 | Information disclosure, sandbox escape in the Security: Process Sandboxing component | 8.6 | 0.0034 | None reported |
| High | CVE-2026-8966 | Information disclosure in the IP Protection component | 7.5 | 0.0033 | None reported |
| High | CVE-2026-8967 | Information disclosure in the Graphics: WebGPU component | 7.5 | 0.0033 | None reported |
| High | CVE-2026-8972 | Privilege escalation in the WebRTC: Audio/Video component | 8.8 | 0.0033 | None reported |
| High | CVE-2026-8965 | Information disclosure in the DOM: Security component | 7.5 | 0.0032 | None reported |
| High | CVE-2026-8961 | Spoofing issue in the Form Autofill component | 7.5 | 0.0032 | None reported |
| High | CVE-2026-8970 | Privilege escalation in the Security component | 8.8 | 0.0031 | None reported |
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