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Vulnerability DatabaseCVE-2025-5271

CVE-2025-5271: 
Mozilla Firefox vulnerability analysis and mitigation

Overview

CVE-2025-5271 is a security vulnerability discovered in Firefox versions prior to 139, where the DevTools preview feature failed to respect Content Security Policy (CSP) headers. The vulnerability was reported by Satoki Tsuji and was officially disclosed on May 27, 2025 (Mozilla Advisory, NVD).

Technical details

The vulnerability stems from the DevTools preview functionality ignoring Content Security Policy headers when previewing responses. The issue has been assigned a CVSS v3.1 base score of 6.5 (MEDIUM) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N. The vulnerability is classified under CWE-116 (Improper Encoding or Escaping of Output) (NVD).

Impact

The vulnerability has been rated as having a low impact. By bypassing CSP headers, the flaw could potentially allow content injection attacks when using the DevTools preview feature (Mozilla Advisory).

Mitigation and workarounds

The vulnerability has been fixed in Firefox version 139. Users are advised to update to this version or later to mitigate the risk. No specific workarounds have been provided for users who cannot immediately update (Mozilla Advisory).

Additional resources

Source: This report was generated using AI

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