CVE-2026-61816

/// Technical description

zbateson/mail-mime-parser is a mail mime parser alternative to PHP's imap* functions and Pear libraries for reading messages in Internet Message Format RFC 822. Starting in version 2.0.0 and prior to version 3.0.6 and 4.0.2, an uncontrolled resource consumption / algorithmic complexity vulnerability (CWE-400) affects any application that parses untrusted email with this library. Three independent parsing paths are super-linear in cost, so a byte-size cap on the caller side does **not** bound the work done. A crafted message under 2 MB can consume seconds of CPU or hundreds of megabytes to multiple gigabytes of memory (leading to an out-of-memory kill), enabling denial of service. The parse is lazy, but the cost is paid on the first `getAllParts()` or content read. This is fxed in 4.0.2 and 3.0.6. The fixes add configurable limits on multipart nesting depth and on header count / total header size (recording a parse error past the threshold rather than throwing), and change sibling appe

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References