CVE-2026-5735CRITICAL 9.8EPSS p22.1%

CVE-2026-5735CVE-2026-5735

Description

Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2 and Thunderbird 149.0.2.

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
EPSS0.31% probability of exploitation · percentile 22.1% · 2026-06-19T12:03:05Z
Published2026-04-07
Last modified2026-05-10

Underlying weaknesses· 2

CWE-787CWE-125

References

  1. https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025475%2C2025477
  2. https://www.mozilla.org/security/advisories/mfsa2026-25/
  3. https://www.mozilla.org/security/advisories/mfsa2026-28/

2

TypeTargetConfidenceTier
WeaknessOut-of-bounds Readcwe-1250%live
WeaknessOut-of-bounds Writecwe-7870%live

Related by meaning· 6

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

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