CVE-2025-5271EPSS p21.1%

CVE-2025-5271CVE-2025-5271

mozilla / firefox

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.

Scoring

CVSS 6.5 ()
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS0.30% probability of exploitation · percentile 21.1% · 2026-10-05T12:00:23Z
Last modified2026-09-30
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.