Multiple Exim Mail Server Flaws Allow Crashes via Malicious DNS Data

Exim released version 4.99.2 to patch four security vulnerabilities (CVE-2026-40684–40687) that can lead to denial-of-service, heap memory corruption, or potential data leakage via malformed DNS responses, corrupted JSON headers, oversized UTF-8 characters, and SPA authentication handling; administrators are urged to update immediately as older releases are no longer maintained.