PYSEC-2026-2211

At a glance

Published: 2026-07-08 17:17 UTC
Updated: 2026-07-13 07:15 UTC
CVE: CVE-2026-59923
Aliases: GHSA-8c25-4j27-2rv3
CVSS_V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Description

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, HTMLRenderer.safe_url() does not block percent-encoded javascript URIs, allowing attacker-supplied Markdown links or images to bypass URL protections and execute script in rendered HTML. This issue is fixed in version 3.3.0.

Affected packages

Package	Versions
PyPI · mistune	introduced 0, fixed 3.3.0

References

https://github.com/lepture/mistune/releases/tag/v3.3.0 ADVISORY
https://github.com/lepture/mistune/commit/c7101fcbb6e8790e8e39157c5ca2238fc6dd6cbc FIX
https://github.com/lepture/mistune/security/advisories/GHSA-8c25-4j27-2rv3 EVIDENCE

Sources

Source	Licence
OSV.dev	CC-BY 4.0 — PyPA Advisory Database