Improper Encoding or Escaping of Output Affecting Firefox package, versions [,139)
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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- published4 Jun 2025
- disclosed27 May 2025
- creditSatoki Tsuji
Introduced: 27 May 2025
NewCVE-2025-5271 (opens in a new tab)How to fix?
Upgrade Firefox to version 139 or higher.
Overview
Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output via the Devtools response preview feature. An attacker can inject malicious content by exploiting the lack of Content Security Policy (CSP) header enforcement in the preview functionality.