CVE-2021-39175: Hedgedoc

Medium severity, CVSS 6.1. EPSS: 0.6% chance of exploitation in the next 30 days.

HedgeDoc is a platform to write and share markdown. In versions prior to 1.9.0, an unauthenticated attacker can inject arbitrary JavaScript into the speaker-notes of the slide-mode feature by embedding an iframe hosting the malicious code into the slides or by embedding the HedgeDoc instance into another page. The problem is patched in version 1.9.0. There are no known workarounds aside from upgrading.

Affected products

• Hedgedoc Hedgedoc: before 1.9.0 (fixed in 1.9.0)

Published 2021-08-30. Last modified 2026-06-17.