CVE-2025-6424
firefox-esr - security update
9.8
CRITICAL
CVSS 3.1
EPSS 1.1%
Description
A use-after-free in FontFaceSet resulted in a potentially exploitable crash. This vulnerability was fixed in Firefox 140, Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
How to fix CVE-2025-6424
To remediate CVE-2025-6424, upgrade the affected package to a fixed version below.
- Debian/firefox-esr—upgrade to 128.12.0esr-1~deb11u1 or later
- —upgrade to 128.12.0esr-1~deb11u1 or later
- —upgrade to 128.12.0esr-1~deb12u1 or later
- —upgrade to 1:128.12.0esr-1~deb11u1 or later
Is CVE-2025-6424 being exploited?
Low — EPSS is 1.1%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 128.12.0esr-1~deb11u1
- from 0, < 128.12.0esr-1~deb11u1
- from 0, < 128.12.0esr-1~deb12u1
- from 0, < 1:128.12.0esr-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |