XSS in Redaxo Core
CVE-2026-63001
REDAXO is a PHP-based content management system. Prior to 5.21.2, the mediaIsInUse() handler in redaxo/src/addons/media_manager/lib/media_manager.php inserts a Media Manager type name into raw backend warning HTML without escaping it when invoked through MEDIA_IS_IN_USE. An administrator with Media Manager access can store HTML in a type name, and the payload executes in another administrator's browser when that administrator tries to delete media referenced by the type's effects, enabling session theft or unauthorized backend actions. This issue is fixed in version 5.21.2.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (9.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 9.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Redaxo Core — versions < 5.21.2
- Redaxo
Weakness classification (CWE)
References
- github.com/redaxo/core/security/advisories/GHSA-mf2p-wjp4-99pq (Exploit, Vendor Advisory)
- github.com/redaxo/core/pull/6581 (Patch, Issue Tracking)
- github.com/redaxo/core/commit/2daaa3a30570bc76a82f63fd21fb8c9c2cd5dc7c (Patch)
- github.com/redaxo/core/releases/tag/5.21.2 (Release Notes)
Frequently asked questions
- What is CVE-2026-63001?
- CVE-2026-63001 is a medium-severity vulnerability in Redaxo Core, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-09-23.
- How severe is CVE-2026-63001?
- Medium severity. CVSS v3 base score is 4.8 out of 10.