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CVE-2025-6424Use-after-free in FontFaceSet
- 9.8CriticalCVSS base score
- 7.9%Exploitation in 30 daysEPSS · top 5.2% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By mozilla
- 4 days later
· 4 days later
Published
- 10 months later
· 10 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 7.9% · top 5.2% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- unaffected 115.25 – ≤ 115.*
- unaffected 128.12 – ≤ 128.*
- unaffected 140 – ≤ *
- unaffected 128.12 – ≤ 128.*
- unaffected 140 – ≤ *
References
References8
- https://bugzilla.mozilla.org/show_bug.cgi?id=1966423 (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-51/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-52/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-53/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-54/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-55/ (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-19086 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-6424)Record last updated .