New Exim BDAT Vulnerability Exposes GnuTLS Builds to Potential Code Execution

Exim released security updates to fix CVE-2026-45185 (Dead.Letter), a use-after-free in BDAT message parsing when a TLS close_notify is received under GnuTLS, which can corrupt heap allocator metadata and enable potential remote code execution on Exim builds compiled with USE_GNUTLS=yes (affecting versions 4.97–4.99.2); users should upgrade to 4.99.3 immediately as no mitigations are available.