Saint Dead.Letter

Technical record

Disclosed on

May 12 2026

CVE

CVE-2026-45185

CVSS

9.8

Product

Exim · Exim

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.

Sources: xbow.com