Protection Mechanism Failure Affecting Firefox-ESR package, versions [,140.14)[141.0,153.1)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-FIREFOXESR-19427618
- published29 Aug 2026
- disclosed18 Aug 2026
- creditUnknown
Introduced: 18 Aug 2026
NewCVE-2026-74959 (opens in a new tab)How to fix?
Upgrade Firefox-ESR to version 140.14, 153.1 or higher.
Overview
Affected versions of this package are vulnerable to Protection Mechanism Failure through the Cache API component. An attacker can bypass intended security mitigations by exploiting flaws in the implementation, potentially leading to unauthorized access or manipulation of cached data.