VULNERABILITY INTELLIGENCE

CVE-2025-69534

CVSS score7.5 HIGH
EPSS probability0.66%
CISA KEVNot currently listed
Published2026-03-05
Last modified2026-09-07
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

Python-Markdown version 3.8 contain a vulnerability where malformed HTML-like sequences can cause html.parser.HTMLParser to raise an unhandled AssertionError during Markdown parsing. Because Python-Markdown does not catch this exception, any application that processes attacker-controlled Markdown may crash. This enables remote, unauthenticated Denial of Service in web applications, documentation systems, CI/CD pipelines, and any service that renders untrusted Markdown. The issue was acknowledged by the vendor and fixed in version 3.8.1. This issue causes a remote Denial of Service in any application parsing untrusted Markdown, and can lead to Information Disclosure through uncaught exceptions.

Weakness classification

  • 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-400
  • 0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-617

Primary references