by Kastro
Paper/Archive/CVE-2026-92238

CVE-2026-92238

Mozilla Thunderbird — Ambiguous parsing of mail headers

EPSS 0.5%CVSS 9.8
critical.is priorityof 100
39
CVSS 9.8 (ADP)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 45.4.454 × 209.1No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

Affected

ProductAffectedFixed inSource
Thunderbirdsee advisory140.16CNA

Scores by source

CISA ADP9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refbugzilla.mozilla.org/show_bug.cgi?id=2060601refmozilla.org/security/advisories/mfsa2026-94refmozilla.org/security/advisories/mfsa2026-95refmozilla.org/security/advisories/mfsa2026-96