Mammoth is vulnerable to Directory Traversal
Date: 2025-10
Affected: nuget/Mammoth, pip/mammoth, maven/org.zwobble.mammoth:mammoth
Attack vector: path-traversal
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2025-11849
CWE: CWE-22
CVSS: 9.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:H)

Versions of the package mammoth from 0.3.25 and before 1.11.0; versions of the package mammoth from 0.3.25 and before 1.11.0; versions of the package mammoth before 1.11.0; versions of the package org.zwobble.mammoth:mammoth before 1.11.0 are vulnerable to Directory Traversal due to the lack of path or file type validation when processing a docx file containing an image with an external link (r:link attribute instead of embedded r:embed). The library resolves the URI to a file path and after reading, the content is encoded as base64 and included in the HTML output as a data URI. An attacker can read arbitrary files on the system where the conversion is performed or cause an excessive resources consumption by crafting a docx file that links to special device files such as /dev/random or /dev/zero.


Mitigations:

Architectural layers (MAESTRO):