CVE-2025-68142
MEDIUM5.3EPSS 0.08%PyMdown Extensions has a ReDOS bug in its Figure Capture extension
Published: 12/16/2025Modified: 5/31/2026
Description
PyMdown Extensions is a set of extensions for the `Python-Markdown` markdown project. Versions prior to 10.16.1 have a ReDOS bug found within the figure caption extension (`pymdownx.blocks.caption`). In systems that take unchecked user content, this could cause long hanges when processing the data if a malicious payload was crafted. This issue is patched in Release 10.16.1. As a workaround, those who process unknown user content without timeouts or other safeguards in place to prevent really large, malicious content being aimed at systems may avoid the use of `pymdownx.blocks.caption` until they're able to upgrade.
Affected packages (2)
- Debian/pymdown-extensionsfrom 0
- PyPI/pymdown-extensionsfrom 0, < 10.16.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U |
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2025-68142
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2025-68142
- PATCHhttps://github.com/facelessuser/pymdown-extensions
- WEBhttps://github.com/facelessuser/pymdown-extensions/commit/b50d15a56850ed1408a284bba81cc019c6bd72e8
- WEBhttps://github.com/facelessuser/pymdown-extensions/security/advisories/GHSA-r6h4-mm7h-8pmq
- WEBhttps://pypi.org/project/pymdown-extensions/10.16.1