CVE-2026-43964: Postfix Buffer Over-Read Crash Flaw

🟡 Medium | Source: Microsoft Security Response Center A buffer over-read vulnerability in Postfix mail transfer agent (versions before 3.8.16, 3.9.10, and 3.10.9) can cause the process to crash when it encounters a malformed enhanced status code missing text after the third numeric segment. This is a denial-of-service risk affecting any system running a vulnerable Postfix version, including those used within Azure-hosted infrastructure. While the vulnerability does not appear to allow remote code execution, an attacker able to deliver a crafted response could disrupt mail delivery services. ...

4 June 2026 · ZX Cloud Security