Vulnerability Description
Use-after-free in the JavaScript: WebAssembly 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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 140.14.0 |
| Mozilla | Thunderbird | < 140.14.0 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2052688Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-74/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-76/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-77/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-78/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-79/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-80/Vendor Advisory
FAQ
What is CVE-2026-74936?
CVE-2026-74936 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Use-after-free in the JavaScript: WebAssembly 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.
How severe is CVE-2026-74936?
CVE-2026-74936 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-74936?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.