Vulnerability Description
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mistune Project | Mistune | < 3.3.0 |
Related Weaknesses (CWE)
References
- https://github.com/lepture/mistune/commit/96d0f57f8fe9eeb06bb4cff521962a27d7c402Patch
- https://github.com/lepture/mistune/releases/tag/v3.3.0Release Notes
- https://github.com/lepture/mistune/security/advisories/GHSA-c8j7-8cv4-2xmqExploitVendor Advisory
- https://github.com/lepture/mistune/security/advisories/GHSA-c8j7-8cv4-2xmqExploitVendor Advisory
FAQ
What is CVE-2026-59922?
CVE-2026-59922 is a vulnerability with a CVSS score of 7.5 (HIGH). Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugin...
How severe is CVE-2026-59922?
CVE-2026-59922 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-59922?
Check the references section above for vendor advisories and patch information. Affected products include: Mistune Project Mistune.