Vulnerability Details CVE-2026-45185
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 24.1%
CVSS Severity
CVSS v3 Score 9.8
References
- https://code.exim.org/exim/wiki/wiki/EximSecurity
- https://exim.org
- https://exim.org/static/doc/security/CVE-2026-45185.txt
- https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/
- https://news.ycombinator.com/item?id=48111748
- https://www.openwall.com/lists/oss-security/2026/05/12/4
- https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-exim
- http://www.openwall.com/lists/oss-security/2026/05/12/25
Products affected by CVE-2026-45185
-
cpe:2.3:a:exim:exim:4.97
-
cpe:2.3:a:exim:exim:4.97.1
-
cpe:2.3:a:exim:exim:4.98
-
cpe:2.3:a:exim:exim:4.98.1
-
cpe:2.3:a:exim:exim:4.98.2
-
cpe:2.3:a:exim:exim:4.99
-
cpe:2.3:a:exim:exim:4.99.1