CVE-2026-53427 Cross-site scripting in MDEx via unescaped highlight_lines_class code-fence attribute

Improper Neutralization of Input During Web Page Generation 'Cross-site Scripting' vulnerability in leandrocp MDEx allows stored or reflected cross-site scripting via attacker-controlled Markdown. When syntax highlighting and full info-string forwarding render: fullinfostring: true are enabled, t...

OESA-2026-1787 python-markdown security update

This is a Python implementation of John Gruber’s Markdown. It is almost completely compliant with the reference implementation, though there are a few known issues. Security Fixes: Python-Markdown version 3.8 contain a vulnerability where malformed HTML-like sequences can cause...