What’s Vulnerable › Vulnerabilities

CVE-2025-11849

• Severity: critical (CVSS 9.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-10-17 · updated 2026-10-19
• Weakness: CWE-22

Description

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 products

• mammoth: from 0.3.25 before 1.11.0; before 1.11.0 — fixed in 1.11.0
• org.zwobble.mammoth:mammoth: before 1.11.0 — fixed in 1.11.0

How to fix

Upgrade to a fixed version: mammoth 1.11.0; org.zwobble.mammoth:mammoth 1.11.0. Check the vendor advisory for mitigations.

References

• https://gist.github.com/AudunWA/4d690d9ae5efdafe7cf71d9c2ee90a10
• https://github.com/mwilliamson/mammoth.js/commit/c54aaeb43a7941317c1f3c119ffa92090f988820
• https://security.snyk.io/vuln/SNYK-DOTNET-MAMMOTH-13561968
• https://security.snyk.io/vuln/SNYK-JAVA-ORGZWOBBLEMAMMOTH-13561969
• https://security.snyk.io/vuln/SNYK-JS-MAMMOTH-13554470
• https://security.snyk.io/vuln/SNYK-PYTHON-MAMMOTH-13561967
• https://gist.github.com/AudunWA/4d690d9ae5efdafe7cf71d9c2ee90a10

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