CVE-2025-5271

Devtools' preview ignored CSP headers

State: Published
Severity: 6.5 Medium
Published: May 27, 2025
Updated: Apr 13, 2026
Reserved: May 27, 2025

Description

Previewing a response in Devtools ignored CSP headers, which could have allowed content injection attacks. This vulnerability was fixed in Firefox 139 and Thunderbird 139.

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N	CISA-ADP

Weaknesses

CWE-116 Improper Encoding or Escaping of Output

Affected Products

Product	Versions
FirefoxMozilla	139 and laterNot affected
ThunderbirdMozilla	139 and laterNot affected

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1920348
https://www.mozilla.org/security/advisories/mfsa2025-42/
https://www.mozilla.org/security/advisories/mfsa2025-45/

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