Uncontrolled Resource Consumption
CVE-2025-69534
Summary
Python-Markdown version through 3.8 contains 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.
- LOW
- NETWORK
- NONE
- UNCHANGED
- NONE
- NONE
- NONE
- HIGH
CWE-400 - Uncontrolled resource consumption
An uncontrolled resource allocation attack (also known as resource exhaustion attack) triggers unauthorized overconsumption of the limited resources in an application, such as memory, file system storage, database connection pool entries, and CPU. This may lead to denial of service for valid users and degradation of the application's functionality as well as that of the host operating system.
References
Advisory Timeline
- Published