Vulnerability Description
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the Include directive in src/mistune/directives/include.py detects only direct self-includes and not indirect cycles, allowing two markdown files that include each other to trigger unbounded recursion, raise RecursionError, and crash the rendering request. This issue is fixed in version 3.3.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mistune Project | Mistune | < 3.3.0 |
Related Weaknesses (CWE)
References
- https://github.com/lepture/mistune/commit/1bef343ade163fc3bb95572b15be720084cdb9Patch
- https://github.com/lepture/mistune/releases/tag/v3.3.0Release Notes
- https://github.com/lepture/mistune/security/advisories/GHSA-8mpj-m6qm-5qr8ExploitThird Party Advisory
FAQ
What is CVE-2026-59927?
CVE-2026-59927 is a vulnerability with a CVSS score of 5.3 (MEDIUM). Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the Include directive in src/mistune/directives/include.py detects only direct self-includes and not indirect cycles, al...
How severe is CVE-2026-59927?
CVE-2026-59927 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-59927?
Check the references section above for vendor advisories and patch information. Affected products include: Mistune Project Mistune.