Emerging Threat: (CVE-2026-45185) Exim Remote Code Execution via BDAT over GnuTLS
CVE-2026-45185, nicknamed Dead.Letter, is a use-after-free vulnerability in the BDAT message body parsing path of Exim, the open-source Mail Transfer Agent that runs a large share of the internet's email servers. The flaw lives in the GnuTLS-backed TLS path, where Exim can free its internal transfer buffer during a TLS shutdown while the SMTP state machine still holds a reference to it.