Medium 5.3Published Jul 8, 2026

CVE-2026-59927Mistune is a Python Markdown parser with renderers and plugins.

Updated under an hour ago (2026-10-19 07:10 UTC)

Does this affect you?

It affects mistune_project mistune. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

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, 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: 5.3 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE): CWE-674, CWE-755
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/1bef343ade163fc3bb95572b15be720084cdb993patch
https://github.com/lepture/mistune/releases/tag/v3.3.0release-notes
https://github.com/lepture/mistune/security/advisories/GHSA-8mpj-m6qm-5qr8exploit, third-party-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.