What’s Vulnerable › Vulnerabilities

CVE-2026-21857: Redaxo has Path Traversal in Backup Addon Leading to Arbitrary File Read

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-01-07 · updated 2026-06-17
• Weakness: CWE-22

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.

Affected products

• redaxo: before 5.20.2 — fixed in 5.20.2

How to fix

Upgrade to a fixed version: redaxo 5.20.2. Check the vendor advisory for mitigations.

References

• https://github.com/redaxo/redaxo/releases/tag/5.20.2
• https://github.com/redaxo/redaxo/security/advisories/GHSA-824x-88xg-cwrv
• https://github.com/redaxo/redaxo/security/advisories/GHSA-824x-88xg-cwrv

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