CVE-2026-59923

Published: Jul 8, 2026Modified: Jul 9, 2026

6.1

Vector

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

Exploitability: 2.8 / Impact: 2.7

Source: security-advisories@github.com (Secondary)

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 (1)

Products: Mistune Project: Mistune

Mistune Project

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Mistune Project Mistune	Before 3.3.0

Related CWEs

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

References (4)

https://github.com/lepture/mistune/commit/c7101fcbb6e8790e8e39157c5ca2238fc6dd6cbc

Source: security-advisories@github.com

Patch

https://github.com/lepture/mistune/releases/tag/v3.3.0

Source: security-advisories@github.com

Release Notes

https://github.com/lepture/mistune/security/advisories/GHSA-8c25-4j27-2rv3

Source: security-advisories@github.com

ExploitVendor Advisory

https://github.com/lepture/mistune/security/advisories/GHSA-8c25-4j27-2rv3

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

ExploitVendor Advisory

Timeline

No history available yet.