CVE-2026-45185

Name	CVE-2026-45185
Description	Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.
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)
References	DLA-4580-1, DSA-6265-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
exim4 (PTS)	bookworm, bookworm (security)	4.96-15+deb12u10	fixed
	trixie (security), trixie	4.98.2-1+deb13u4	fixed
	forky	4.100-1	fixed
	sid	4.100-3	fixed

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

Package	Type	Release	Fixed Version	Origin
exim4	source	bullseye	4.94.2-7+deb11u5	DLA-4580-1
exim4	source	bookworm	4.96-15+deb12u9	DSA-6265-1
exim4	source	trixie	4.98.2-1+deb13u2	DSA-6265-1
exim4	source	(unstable)	4.99.2-2

Notes

https://code.exim.org/exim/exim/commit/040c1ce6889f435206677ed532c9a4185cf0bcaf
https://www.openwall.com/lists/oss-security/2026/05/12/4
https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/EXIM-Security-2026-05-01.1.txt
https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-exim