CVE-2026-44898
MEDIUM
6,1
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: required
Scope: changed
Confidentiality: low
Integrity: low
Availability: none
Description
AI Translation Available
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_toc_ul() builds a <ul> table-of-contents tree from a list of (level, id, text) tuples. Both the id value (used as href='#<id>') and the text value (used as the visible link label) are inserted into <a> tags via a plain Python format string — with no HTML escaping applied to either value. When heading IDs are derived from user-supplied heading text (the standard use-case for readable slug anchors), an attacker can craft a heading whose text breaks out of the href='#...' attribute context, injecting arbitrary HTML tags including <script> blocks directly into the rendered TOC. This vulnerability is fixed in 3.2.1.
79
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
StableCommon Consequences
Security Scopes Affected:
Access Control
Confidentiality
Integrity
Availability
Potential Impacts:
Bypass Protection Mechanism
Read Application Data
Execute Unauthorized Code Or Commands
Applicable Platforms
Technologies:
AI/ML, Web Based, Web Server
https://github.com/lepture/mistune/releases/tag/v3.2.1
https://github.com/lepture/mistune/security/advisories/GHSA-6269-cqxg-mhhv