CVE-2025-6424CRITICAL 9.8EPSS p85.9%

CVE-2025-6424CVE-2025-6424

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 3.19.8 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS3.06% probability of exploitation · percentile 85.9% · 2026-06-19T12:03:05Z
Published2025-06-24
Last modified2026-04-13

Underlying weaknesses· 1

CWE-416

References

  1. https://bugzilla.mozilla.org/show_bug.cgi?id=1966423
  2. https://www.mozilla.org/security/advisories/mfsa2025-51/
  3. https://www.mozilla.org/security/advisories/mfsa2025-52/
  4. https://www.mozilla.org/security/advisories/mfsa2025-53/
  5. https://www.mozilla.org/security/advisories/mfsa2025-54/
  6. https://www.mozilla.org/security/advisories/mfsa2025-55/
  7. https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html
  8. https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html

1

TypeTargetConfidenceTier
WeaknessUse After Freecwe-4160%live

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Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.