CVE-2026-105829: Thephpleague Commonmark

Medium severity, CVSS 6.1. EPSS: 0.2% chance of exploitation in the next 30 days.

League CommonMark from 1.3.0 before 2.10.2 contains a cross-site scripting vulnerability that allows users posting Markdown to bypass the DisallowedRawHtml extension by ending raw HTML with a bare disallowed tag name. Attackers can place a lone <script or <iframe line followed by a block supplying attributes like src or onload, executing stored scripts in viewers' browsers under default GFM settings.

Affected products

• Thephpleague Commonmark

Published 2026-10-08. Last modified 2026-10-10.