Origin Validation Error Affecting Firefox-ESR package, versions [,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.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-UNMANAGED-FIREFOXESR-19427663
- published29 Aug 2026
- disclosed18 Aug 2026
- creditUnknown
Introduced: 18 Aug 2026
NewCVE-2026-74956 (opens in a new tab)How to fix?
Upgrade Firefox-ESR to version 153.1 or higher.
Overview
Affected versions of this package are vulnerable to Origin Validation Error via the Service Workers process. An attacker can access resources or data from a different origin by exploiting improper enforcement of same-origin policy.