CVE-2025-6424

critical

Description

A use-after-free in FontFaceSet resulted in a potentially exploitable crash. This vulnerability affects Firefox < 140, Firefox ESR < 115.25, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

References

https://www.mozilla.org/security/advisories/mfsa2025-55/

https://www.mozilla.org/security/advisories/mfsa2025-54/

https://www.mozilla.org/security/advisories/mfsa2025-53/

https://www.mozilla.org/security/advisories/mfsa2025-52/

https://www.mozilla.org/security/advisories/mfsa2025-51/

https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html

https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html

https://bugzilla.mozilla.org/show_bug.cgi?id=1966423

Details

Source: Mitre, NVD

Published: 2025-06-24

Updated: 2025-11-03

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

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