CVE-2026-45185
CRITICALDescription
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.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 65% of all known CVEs.
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
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-28.