CVE-2026-21857

07.01.2026, 23:15

REDAXO is a PHP-based content management system. Prior to version 5.20.2, authenticated users with backup permissions can read arbitrary files within the webroot via path traversal in the Backup addon's file export functionality. The Backup addon does not validate the `EXPDIR` POST parameter against the UI-generated allowlist of permitted directories. An attacker can supply relative paths containing `../` sequences (or even absolute paths inside the document root) to include any readable file in the generated `.tar.gz` archive. Version 5.20.2 fixes this issue.

Path Traversal

Provider	Type	Base Score	Vector
NIST	NIST	UNKNOWN	---
GitHub_M	CNA	---	---
CISA-ADP	ADP	---	---

Base Score

CVSS 3.x

EPSS Score

Percentile: 13%

Common Weakness Enumeration

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

References

https://github.com/redaxo/redaxo/releases/tag/5.20.2

https://github.com/redaxo/redaxo/security/advisories/GHSA-824x-88xg-cwrv