CVE-2025-4091HIGH 8.1EPSS p31.9%

CVE-2025-4091CVE-2025-4091

Description

Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 128.9, and Thunderbird 128.9. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Thunderbird 138, and Thunderbird 128.10.

Scoring

CVSS 3.18.1 (HIGH)
VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS0.40% probability of exploitation · percentile 31.9% · 2026-06-19T12:03:05Z
Published2025-04-29
Last modified2026-04-13

Underlying weaknesses· 1

CWE-119

References

  1. https://bugzilla.mozilla.org/buglist.cgi?bug_id=1951161%2C1952105
  2. https://www.mozilla.org/security/advisories/mfsa2025-28/
  3. https://www.mozilla.org/security/advisories/mfsa2025-29/
  4. https://www.mozilla.org/security/advisories/mfsa2025-31/
  5. https://www.mozilla.org/security/advisories/mfsa2025-32/
  6. https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html

1

TypeTargetConfidenceTier
WeaknessImproper Restriction of Operations within the Bounds of a Memory Buffercwe-1190%live

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.

CVE
CVE-2025-4093
CVE
CVE-2025-1017
CVE
CVE-2025-9187
CVE
CVE-2025-6436
CVE
CVE-2026-0891
CVE
CVE-2025-1016
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.