CVE-2026-59929
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, the safe_url filter in src/mistune/renderers/html.py blocks only javascript:, vbscript:, file:, and data: schemes, allowing legacy or chained schemes such as feed:, view-source:, jar:, livescript:, mocha:, ms-its:, mk:, and res: to reach rendered href and src attributes and potentially execute script in affected user agents. This issue is fixed in version 3.3.0.
Affected (1)
Products: Mistune Project: Mistune
Configuration A
| Vulnerable Software | Affected Versions |
|---|---|
| Before 3.3.0 |
Related CWEs
CWE-184
Incomplete List of Disallowed Inputs
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete, leading to resultant weaknesses.
CWE-79
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 (3)
Source: security-advisories@github.com
Patch
Source: security-advisories@github.com
Release Notes
Source: security-advisories@github.com
ExploitThird Party Advisory
Timeline
No history available yet.