by Kastro
Paper/Archive/CVE-2026-92240

CVE-2026-92240

Mozilla Thunderbird — Out-of-bounds read in IMAP response parser

EPSS 0.6%CVSS 9.1
critical.is priorityof 100
37
CVSS 9.1 (ADP)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 50.1.501 × 2010.0No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP response parser by sending an untagged '* ID' response, crashing Thunderbird. The affected parsing path is reachable before authentication. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

Affected

ProductAffectedFixed inSource
Thunderbirdsee advisory140.16CNA

Scores by source

CISA ADP9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refbugzilla.mozilla.org/show_bug.cgi?id=2069113refmozilla.org/security/advisories/mfsa2026-94refmozilla.org/security/advisories/mfsa2026-95refmozilla.org/security/advisories/mfsa2026-96