CVE-2026-45185
CRITICAL 9.8EPSS 0.9%
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.
- Affected
- Exim
- CVSS v3.1 MITRE
- 9.8 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS
- 0.94% chance of exploitation in the next 30 days, 60th percentile
- Published
- 2026-05-12
- Updated
- 2026-05-14
Proof-of-concept exploits (2)
- 0init/CVE-2026-451850★ · 2026-08-07
- materaj2/cve-2026-45185-detection-script0★ · 2026-05-14
Security advisories
- https://code.exim.org/exim/wiki/wiki/EximSecurity
- http://www.openwall.com/lists/oss-security/2026/05/12/25
- https://www.openwall.com/lists/oss-security/2026/05/12/4
- https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-exim
- https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1
- https://exim.org
- https://news.ycombinator.com/item?id=48111748