CVE-2026-21857

MEDIUM

Redaxo < 5.20.2 - Path Traversal

Title source: rule

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.

Exploits (1)

nomisec WRITEUP
by lukasz-rybak · poc
https://github.com/lukasz-rybak/CVE-2026-21857

Scores

CVSS v3 6.5
EPSS 0.0003
EPSS Percentile 7.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

Details

CWE
CWE-22 CWE-24
Status published
Products (2)
redaxo/redaxo < 5.20.2
redaxo/source 0 - 5.20.2Packagist
Published Jan 07, 2026
Tracked Since Feb 18, 2026