Exposure of Resource to Wrong Sphere 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-19427528
- published29 Aug 2026
- disclosed18 Aug 2026
- creditUnknown
Introduced: 18 Aug 2026
NewCVE-2026-74960 (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 Exposure of Resource to Wrong Sphere through improper enforcement of site isolation in the WebExtensions component. An attacker can access data from other sites by exploiting this weakness in process separation.