cvedb.io
CVE-2025-69534
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-03-05T15:16:11.243 · Last modified 2026-06-30T03:16:59.773

Summary

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.

Affected products

python-markdown — markdown

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.