Exim
Exim 4.99.2 Patches Four Mail Server Flaws: Heap Corruption via JSON Headers, DNS Poisoning, and SPA Auth Bugs
Exim 4.99.2 fixes four memory-safety bugs (CVE-2026-40684 through 40687) in the world's most-deployed MTA, including a JSON heap-write reachable from untrusted headers.