CVE-2026-105219

Summary

Mammoth.js is vulnerable to a regular expression denial of service (ReDoS) attack that can block the Node.js event loop when processing crafted .docx files with unterminated quoted strings containing repeated backslash escapes in style maps, potentially causing a denial of service for all users of the application.

Exploitability

Exploitation is relatively straightforward as attackers only need to upload a specially crafted .docx file with an unterminated quoted string of repeated backslash escapes in the mammoth/style-map section, requiring no user interaction or authentication.

Blast radius

The impact could be significant across all users of applications using Mammoth.js for .docx processing, potentially leading to widespread service unavailability if the vulnerability is exploited in a document processing pipeline.

Detection

No reliable host or network indicator is derivable from the published description.

Prioritized remediation

Upgrade to Mammoth.js version 1.12.3 or later to address the ReDoS vulnerability in the style map tokeniser.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.