CVE-2026-59929
Published:July 08, 2026
Updated:August 05, 2026
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 Packages
mistune (CONDA):
Affected version(s) >=0.5 <3.3.0Fix Suggestion:
Update to version 3.3.0https://github.com/lepture/mistune.git (GITHUB):
Affected version(s) >=v0.1.0 <v3.3.0Fix Suggestion:
Update to version v3.3.0mistune (PYTHON):
Affected version(s) >=0.1.0 <3.3.0Fix Suggestion:
Update to version 3.3.0mistune (PYTHON):
Affected version(s) >=0.1.0 <3.3.0Fix Suggestion:
Update to version 3.3.0Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.22