CVE-2025-6424
9.8
CRITICAL · CVSS 3.1 · EPSS 4.4% (pctl 91)
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
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.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 4.39% — more likely to be exploited than 91% of all CVEs |
| Weakness | CWE-416 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2025-06-24 |
| Last modified | 2026-10-05 |
Affected (1)
| Vendor | Product |
|---|---|
| mozilla | firefox |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1966423
- https://www.mozilla.org/security/advisories/mfsa2025-51/
- https://www.mozilla.org/security/advisories/mfsa2025-52/
- https://www.mozilla.org/security/advisories/mfsa2025-53/
- https://www.mozilla.org/security/advisories/mfsa2025-54/
- https://www.mozilla.org/security/advisories/mfsa2025-55/
- https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html
- https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html
→ the Explorer · watch your stack · NVD