CVE-2026-92240: critical vulnerability in Mozilla Thunderbird
Out-of-bounds read in IMAP response parser
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.1epss 0.6%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Affected products
Mozilla · ThunderbirdRelated CVEs — Mozilla Thunderbird
In the same product, most dangerous first.