CVE-2026-59927

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 3.1

5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS

0.5% chance of exploitation in the next 30 days; higher than 44% of CVEs (scores of 2026-10-25)

CWEs

CWE-674, CWE-755

Published

2026-07-08

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Affected

• mistune_project:mistune

Packages (OSV)

References

• https://github.com/lepture/mistune/commit/1bef343ade163fc3bb95572b15be720084cdb993
• https://github.com/lepture/mistune/releases/tag/v3.3.0
• https://github.com/lepture/mistune/security/advisories/GHSA-8mpj-m6qm-5qr8

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