Medium severity · published Jan 7, 2026
CVE-2026-21857
REDAXO is a PHP-based content management system
6.5
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 45% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RE
Redaxo · Redaxo
before 5.20.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-21857
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-21857
Release Notes
https://github.com/redaxo/redaxo/releases/tag/5.20.2
Exploit
https://github.com/redaxo/redaxo/security/advisories/GHSA-824x-88xg-cwrv
More from Redaxo
9.8
CVE-2018-18200
There is a SQL injection in Benutzerverwaltung in REDAXO before 5.6.4
9.8
CVE-2018-17831
In REDAXO before 5.6.3, a critical SQL injection vulnerability has been discovered in the rex_list class because of the prepareQuery function in core/lib/list.php, via the…
7.2
CVE-2025-64050
A Remote Code Execution (RCE) vulnerability in the template management component in REDAXO CMS 5.20.0 allows remote authenticated administrators to execute arbitrary operating…
7.2
CVE-2024-46210
An arbitrary file upload vulnerability in the MediaPool module of Redaxo CMS v5.17.1 allows attackers to execute arbitrary code via uploading a crafted file
7.2
CVE-2024-46213
REDAXO CMS v2.11.0 was discovered to contain a remote code execution (RCE) vulnerability