Multiple Exim Mail Server Vulnerabilities Leads to Crash with Malicious DNS data

Exim 4.99.2 was released to patch four critical vulnerabilities that can trigger denial-of-service, heap corruption, and potential data leakage via malformed DNS PTR records (musl-related crash), corrupted JSON configurations, large/malformed UTF-8 header sequences, and a flawed SPA authenticator; administrators are advised to upgrade immediately and validate externally supplied JSON and UTF-8 inputs to reduce automated and targeted exploitation risks.