Client-Side Enforcement of Server-Side Security Affecting Firefox package, versions [,148.0.0)
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-FIREFOX-15345104
- published25 Feb 2026
- disclosed24 Feb 2026
- creditSkywarp
Introduced: 24 Feb 2026
CVE-2026-2803 (opens in a new tab)How to fix?
Upgrade Firefox to version 148.0.0 or higher.
Overview
Affected versions of this package are vulnerable to Client-Side Enforcement of Server-Side Security in the Settings UI component. An attacker can access sensitive information or bypass implemented mitigations by exploiting weaknesses in the handling of user interface elements.