CVE-2026-92240

critical · 9.1

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.

9.1

CVSS

0.7%

EPSS (exploit prob.)

50th

EPSS percentile

2026-09-15

Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Weaknesses

CWE-125

Affected products

Vendor	Product	Affected versions
mozilla	thunderbird	< 140.16.0
mozilla	thunderbird	>= 141.0, < 153.3.0
mozilla	thunderbird	>= 154.0, < 156.0

Check a specific version with /api/v1/cve/match.

References

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

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-92240