CVE-2026-40015

Name	CVE-2026-40015
Description	An attacker that has valid credentials can open many connections to the imap-hibernate service and send invalid commands, which can intermittently cause an out-of-bounds read and crash the process. The crash interrupts hibernated IMAP sessions handled by the affected process, which can cause degradation of service for IMAP. Disable IMAP hibernation. Update to non-vulnerable version. No publicly available exploits are known.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1146018

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
dovecot (PTS)	bookworm, bookworm (security)	1:2.3.19.1+dfsg1-2.1+deb12u6	vulnerable
	trixie (security), trixie	1:2.4.1+dfsg1-6+deb13u6	vulnerable
	forky, sid	1:2.4.5+dfsg1-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
dovecot	source	(unstable)	1:2.4.5+dfsg1-1			1146018

https://documentation.open-xchange.com/dovecot/security/advisories/html/2026/oxdc-adv-2026-0003.html#cve-2026-40015-imap-hibernate-can-be-crashed