Intel

AIKIDO-2026-935898

mammoth is vulnerable to Denial of Service (DoS)

Denial of Service (DoS) Pre-CVE
Found by Aikido Intel before public disclosure or CVE publication.
Published Aug 10, 2026

65

Medium Risk

This Affects:

JSmammoth
1.4.8 - 1.12.0
Fixed in 1.12.1
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TL;DR

When resolving list numbering, the parser follows numStyleLink references between numbering definitions to locate a level. A numbering definition that links to itself, directly or through a cycle, causes the lookup to recurse without termination. Converting a crafted document exhausts the call stack and consumes excessive CPU and memory, crashing or hanging the conversion. The fix tracks already-visited numbering identifiers and stops when a cycle is detected.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range and you convert untrusted or externally supplied documents.

Background info

mammoth is vulnerable to Denial of Service (DoS) in versions 1.4.8 - 1.12.0.

How to fix this

Upgrade the mammoth library to the patch version.