markdownify allows large headline prefixes such as <h9999999>, which causes memory consumption
python-markdownify (aka markdownify) before 0.14.1 allows large headline prefixes such as <h9999999> in addition to <h1> through <h6>. This causes memory consumption.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | markdownify | < 0.14.1 | 0.14.1 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-46656
- https://github.com/matthewwithanm/python-markdownify/issues/143
- https://github.com/matthewwithanm/python-markdownify/commit/959561879693bf4a576f99c6733b50b01186aa08
- https://github.com/matthewwithanm/python-markdownify
- https://github.com/matthewwithanm/python-markdownify/compare/0.14.0...0.14.1
- https://pypi.org/project/markdownify
- https://github.com/advisories/GHSA-7mpr-5m44-h73r
- CVSS vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L- Weakness (CWE)
CWE-1284- Platform
- Python (PyPI)
- Package
markdownify- Disclosed
- 27.04.2025
- Updated
- 11.10.2026 13:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-1604 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-7mpr-5m44-h73r - CC BY 4.0
Vulnerability history: markdownify
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
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