CVE-2025-11849: mammoth · Directory Traversal
Affects mammothSource CVE Database V5
Public exploit available · CVSS 6.4 Medium : upgrade to 1.11.0 as a priority.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 1.1% chance of exploitation in 30 days – higher than 66% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.11.0
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:PExploitation evidence
Disclosed: evidence found.
CVE published 17 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade mammoth and org.zwobble.mammoth to 1.11.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
npmmammothpkg:npm/mammothOther threats | Affected
| Fixed in
|
PyPImammothpkg:pypi/mammothOther threats | Affected
| Fixed in
|
NuGetmammothpkg:nuget/mammothOther threats | Affected
| Fixed in
|
Mavenorg.zwobble.mammothpkg:maven/org.zwobble.mammothOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
- Upgrade mammoth to version 1.11.0 or later where this vulnerability is fixed.
- Implement strict validation and sanitization of DOCX files before processing, rejecting files with external image links or suspicious r:link attributes.
- Run document conversion processes in isolated, sandboxed environments with minimal file system permissions to limit access to sensitive files.
- Monitor and log document processing activities to detect anomalous file access patterns.
- Employ rate limiting and resource usage controls to mitigate potential denial of service from resource exhaustion.
- Educate users and administrators about the risks of processing untrusted DOCX files and enforce policies restricting document sources.
- Consider using alternative libraries or tools with stronger security postures if mammoth is not essential.
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.
References
- security.snyk.io/vuln/SNYK-JS-MAMMOTH-13554470 (opens in a new tab)
- security.snyk.io/vuln/SNYK-PYTHON-MAMMOTH-13561967 (opens in a new tab)
- security.snyk.io/vuln/SNYK-DOTNET-MAMMOTH-13561968 (opens in a new tab)
- security.snyk.io/vuln/SNYK-JAVA-ORGZWOBBLEMAMMOTH-13561969 (opens in a new tab)
- gist.github.com/AudunWA/4d690d9ae5efdafe7cf71d9c2ee90a10 (opens in a new tab)
- github.com/mwilliamson/mammoth.js/commit/c54aaeb43a7941317c1f3c119ffa92090f988820 (opens in a new tab)