mail-mime-parser up to 3.0.5/4.0.1 MIME Parser getAllParts resource consumption

Summaryinfo

A vulnerability was found in mail-mime-parser up to 3.0.5/4.0.1. It has been rated as problematic. This affects the function getAllParts of the component MIME Parser. The manipulation leads to resource consumption. This vulnerability is listed as CVE-2026-61816. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in mail-mime-parser up to 3.0.5/4.0.1 and classified as problematic. This issue affects the function getAllParts of the component MIME Parser. The manipulation with an unknown input leads to a resource consumption vulnerability. Using CWE to declare the problem leads to CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. Impacted is availability. The summary by CVE is:

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 append to O(n). Users should upgrade to one of these (or later) versions. Versions 2.x are also affected but are end-of-life and will not receive patches; users on those lines should upgrade to a fixed release. (Versions prior to 2.0 used a different parser and are not affected by all three paths.) These costs are super-linear, so an input byte-size cap alone does not bound them. Until upgrading, restrict exposure of the parser to untrusted input, and run parsing under a constrained memory_limit and execution time limit so a malicious message fails its own request rather than exhausting the host.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-61816 since 07/10/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 3.0.6 or 4.0.2 eliminates this vulnerability.

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Productinfo

Name

• mail-mime-parser

Version

• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5
• 4.0.0
• 4.0.1

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CPE 2.2info

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