CVE-2026-74959

CriticalCVSS 9.1

Published: 18/08/2026(UTC)Updated: 21/08/2026(UTC)Translated: 19/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.16%

6th percentile - higher than 6% of all known CVEs

Summary

Vulnerability in the Storage: Cache API component involving a mitigation bypass. The flaw was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, and Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

Risk Assessment

The risk of mitigation bypass could allow an attacker to exploit the cache for unauthorized actions, potentially compromising data integrity.

Recommendation

Update Firefox or Thunderbird to the patched version immediately.

Original NVD description (English source)

Mitigation bypass in the Storage: Cache API 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.