---
id: CVE-2025-11849
aliases:
  - GHSA-rmjr-87wv-gf87
  - PYSEC-2026-1603
title: Mammoth is vulnerable to Directory Traversal
summary: Mammoth is vulnerable to Directory Traversal
severity: critical
cvss: 9.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:H'
vendor: mammoth
product: mammoth
ecosystem: npm
affected:
  - 'mammoth >= 0.3.25, < 1.11.0'
  - 'org.zwobble.mammoth:mammoth < 1.11.0'
  - 'mammoth >= 0.3.25, < 1.11.0'
  - Mammoth < 1.11.0
patched:
  - mammoth 1.11.0
  - 'org.zwobble.mammoth:mammoth 1.11.0'
  - mammoth 1.11.0
  - Mammoth 1.11.0
published: '2025-10-17'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-rmjr-87wv-gf87'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-11849'
  - url: >-
      https://github.com/mwilliamson/mammoth.js/commit/c54aaeb43a7941317c1f3c119ffa92090f988820
  - url: 'https://gist.github.com/AudunWA/4d690d9ae5efdafe7cf71d9c2ee90a10'
  - url: 'https://github.com/mwilliamson/java-mammoth'
  - url: 'https://security.snyk.io/vuln/SNYK-DOTNET-MAMMOTH-13561968'
  - url: 'https://security.snyk.io/vuln/SNYK-JAVA-ORGZWOBBLEMAMMOTH-13561969'
  - url: 'https://security.snyk.io/vuln/SNYK-JS-MAMMOTH-13554470'
  - url: 'https://security.snyk.io/vuln/SNYK-PYTHON-MAMMOTH-13561967'
tags:
  - osv
  - npm
epss: 0.0101
epssPercentile: 0.61586
ingestedAt: '2026-07-08T18:25:52.986Z'
---

## Overview

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.

## Affected packages

- `mammoth >= 0.3.25, < 1.11.0`
- `org.zwobble.mammoth:mammoth < 1.11.0`
- `mammoth >= 0.3.25, < 1.11.0`
- `Mammoth < 1.11.0`

## Remediation

Upgrade to a patched release:

- `mammoth 1.11.0`
- `org.zwobble.mammoth:mammoth 1.11.0`
- `mammoth 1.11.0`
- `Mammoth 1.11.0`