Overview
What is CVE-2026-42504?
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
Vulnerability intelligence
CVE-2026-42504 and is rated High severity with a CVSS score of 7.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.