CVE-2019-10905: Parsedown

High severity, CVSS 8.1. EPSS: 1.5% chance of exploitation in the next 30 days.

Parsedown before 1.7.2, when safe mode is used and HTML markup is disabled, might allow attackers to execute arbitrary JavaScript code if a script (already running on the affected page) executes the contents of any element with a specific class. This occurs because spaces are permitted in code block infostrings, which interferes with the intended behavior of a single class name beginning with the language- substring.

Affected products

• Parsedown Parsedown: before 1.7.2 (fixed in 1.7.2)

Published 2019-04-06. Last modified 2026-06-17.