markdownify allows large headline prefixes such as <h9999999>, which causes memory consumption

LOW 3.3CVE-2025-46656 · GHSA-7mpr-5m44-h73r · PYSEC-2026-1604 · Published 26/04/2025 · updated 17/06/2026

In short

CVE-2025-46656 is a LOW (CVSS 3.3) vulnerability affecting markdownify, markdownify (matthewwithanm).
Chance of exploitation in the next 30 days (EPSS): 0.22%, higher than 12.6% of all vulnerabilities.
Fix: update to 0.14.1 or later.

Package	Affected versions	Patched versions
markdownify PyPI	`< 0.14.1`	`0.14.1`
markdownify matthewwithanm	`< 0.14.1`	`0.14.1`

Description

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.

NVD description

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.

References

nvd.nist.gov/vuln/detail/CVE-2025-46656 · ADVISORY
matthewwithanm/python-markdownify · WEB
matthewwithanm/python-markdownify commit 9595618 · WEB
matthewwithanm/python-markdownify · PACKAGE
matthewwithanm/python-markdownify · WEB
pypi.org/project/markdownify · PACKAGE
GitHub Advisory GHSA-7mpr-5m44-h73r · ADVISORY

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