CVE-2026-21857
January 07, 2026
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.
Affected Packages
redaxo/source (PHP):
Affected version(s) >=5.x-dev <5.20.2Fix Suggestion:
Update to version 5.20.2Related Resources (4)
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Contact UsCVSS v4
Base Score:
8.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
HIGH
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.07
