CVE-2026-2777CRITICAL 9.8EPSS p28.5%

CVE-2026-2777CVE-2026-2777

Description

Privilege escalation in the Messaging System component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

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
EPSS0.37% probability of exploitation · percentile 28.5% · 2026-06-19T12:03:05Z
Published2026-02-24
Last modified2026-04-13

Underlying weaknesses· 1

CWE-269

References

  1. https://bugzilla.mozilla.org/show_bug.cgi?id=2015305
  2. https://www.mozilla.org/security/advisories/mfsa2026-13/
  3. https://www.mozilla.org/security/advisories/mfsa2026-14/
  4. https://www.mozilla.org/security/advisories/mfsa2026-15/
  5. https://www.mozilla.org/security/advisories/mfsa2026-16/
  6. https://www.mozilla.org/security/advisories/mfsa2026-17/

1

TypeTargetConfidenceTier
WeaknessImproper Privilege Managementcwe-2690%live

Related by meaning· 6

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

CVE
CVE-2026-4722
CVE
CVE-2026-2782
CVE
CVE-2026-8970
CVE
CVE-2026-0877
CVE
CVE-2026-6761
CVE
CVE-2026-4717
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.