High 7.5Published Jul 8, 2026

CVE-2026-59922Mistune is a Python Markdown parser with renderers and plugins.

Updated under an hour ago (2026-10-19 08:00 UTC)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for mistune_project mistune

Exploited in the last 30 days

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: 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-407, CWE-1333
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jul 9, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

mistune_project mistune mistune_project:mistune	before 3.3.0	NVD

References

https://github.com/lepture/mistune/commit/96d0f57f8fe9eeb06bb4cff521962a27d7c402e7patch
https://github.com/lepture/mistune/releases/tag/v3.3.0release-notes
https://github.com/lepture/mistune/security/advisories/GHSA-c8j7-8cv4-2xmqexploit, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.