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.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade thunderbird | Oct 11, 2026 | Sep 23, 2026 |
| Debian | — | Upgrade thunderbird | Sep 21, 2026 | Sep 15, 2026 |
| Mozilla Thunderbird | — | Upgrade to the latest version of Mozilla ThunderbirdUpgrade to Mozilla Thunderbird version 153.3 | Sep 15, 2026 | Sep 15, 2026 |
| Redhat_linux | — | Upgrade thunderbirdNo solution existsUpgrade thunderbird-debuginfoUpgrade thunderbird-debugsource | Sep 18, 2026 | Sep 15, 2026 |
| Rocky_linux | — | Upgrade thunderbirdUpgrade thunderbird-debugsourceUpgrade thunderbird-debuginfo | Sep 28, 2026 | Sep 25, 2026 |
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