CVE-2026-42504

A flaw was found in the Golang MIME (Multipurpose Internet Mail Extensions) package. A remote attacker could exploit this vulnerability by sending a maliciously-crafted MIME header containing many invalid encoded-words. This could lead to excessive CPU consumption, resulting in a Denial of Service (DoS) for the affected system.

This is rated as an Important severity flaw. A remote attacker could trigger a Denial of Service by sending a crafted MIME header with numerous invalid encoded-words to an application utilizing the affected Golang MIME package. This could lead to excessive CPU consumption on the system processing the malformed header, impacting service availability.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, restrict network access to services that process MIME headers from untrusted sources. Implement input validation and sanitization for all incoming data, especially MIME headers, to prevent maliciously crafted content from being processed by applications utilizing the vulnerable Golang MIME package.