Skip to content
OpenAdvisories
Medium · 6.5 CVE-2025-22602 EUVD-2025-2877

Stored DOM-based XSS (without CSP) via video placeholders in Discourse

Published Feb 4, 2025 · Updated Feb 12, 2025 · Assigned by GitHub_M

Description

Discourse is an open source platform for community discussion. In affected versions an attacker can execute arbitrary JavaScript on users' browsers by posting a malicious video placeholder html element. This issue only affects sites with CSP disabled. This problem has been patched in the latest version of Discourse. Users are advised to upgrade. Users unable to upgrade should enable CSP.

Affected products

VendorProductAffectedFixed
discourse discourse stable: <= 3.3.3, beta: <= 3.4.0.beta3, tests-passed: <= 3.4.0.beta3 —

References