Quick answers
- Is CVE-2026-117538 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-117538 being exploited in the wild.
- How severe is CVE-2026-117538?
- Medium severity, with a CVSS score of 4.1, published 27 October 2026.
- Which products and versions are affected?
- REDAXO Core before 5.21.0.
- Is there a fix for CVE-2026-117538?
- Yes: fixed in 5.21.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-117538 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-117538?
- Check whether you run REDAXO Core at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 5.21.0
Technical details
The function parameter in the backend packages API is concatenated directly into an exception message and rendered via rex_view::message() without HTML escaping, creating a reflected XSS. Exploitation requires a valid backend session, a valid CSRF token, and user interaction (clicking a malicious link). An attacker can execute arbitrary JavaScript in the victim's admin session to access DOM data or perform same-origin requests.
Affected products
- REDAXO core before 5.21.0
Timeline
- 2026-04-09: disclosed
- 2026-10-27: advisory