CVE-2026-117535: REDAXO before 5.21.3 Reflected XSS via opener_link in Media Pool
REDAXO before 5.21.3 contains a reflected cross-site scripting vulnerability in the backend media pool detail page, where the openerlink parameter is rendered without HTML escaping. Unauthenticated attackers can lure logged-in backend users with media permissions into clicking a crafted link. The injected script can then read the CSRF token and perform actions with the victim's permissions, including code execution via template or module edits when the victim is an administrator.
Event History
Frequently Asked Questions
Who is exposed to exploitation?
Logged-in REDAXO backend users who have media permissions can be targeted. An administrator is at higher risk because the injected script can use that user's permissions to edit templates or modules, potentially resulting in code execution.
What does an attacker need to exploit this issue?
The attacker does not need authentication, but must persuade a logged-in backend user with media permissions to click a crafted link. Exploitation requires user interaction.
Are installations on the fixed release affected?
The issue affects REDAXO versions before 5.21.3. Version 5.21.3 is identified as the fixed boundary in the available information.
How could exploitation be detected?
Review requests to the backend media pool detail page for crafted opener_link parameter values, particularly values containing HTML or script-like content. Also investigate unexpected backend actions, especially template or module edits performed under a media-enabled user's account.