CVE-2025-5271

Devtools' preview ignored CSP headers

CVSS 6.5 MEDIUMEPSS 0.2%CWE-116

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 6.5EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

27 May 2025Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected products

Mozilla · Firefox Mozilla · Thunderbird

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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/