VDB
CVE-2026-59922
CVE-2026-59922
PUBLISHED
CVSS 7.5 HIGH
Reported by GitHub_M · Published July 8, 2026
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.
Risk Scores
CVSS 3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| lepture | mistune | < 3.3.0 |
| lepture | mistune | < 3.3.0, < 3.3.0 |
Timeline
- Jul 8, 2026 CVE Published
- Jul 9, 2026 EPSS Score
- Jul 9, 2026 Coalition ESS Score
- Jul 9, 2026 CVE Updated
- Aug 7, 2026 EPSS Score
References
- https://github.com/lepture/mistune/security/advisories/GHSA-c8j7-8cv4-2xmq x_refsource_CONFIRM
- https://github.com/lepture/mistune/commit/96d0f57f8fe9eeb06bb4cff521962a27d7c402e7 x_refsource_MISC
- https://github.com/lepture/mistune/releases/tag/v3.3.0 x_refsource_MISC