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.
References 4
https://bugzilla.mozilla.org/show_bug.cgi?id=2069113
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-94/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-95/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-96/
security@mozilla.org