CVE-2026-21857
MEDIUMREDAXO < 5.20.2 - Authenticated Path Traversal via Backup Addon EXPDIR Parameter
Title source: llmExploitation Summary
EIP tracks 1 public exploit for CVE-2026-21857. PoCs published by lukasz-rybak.
AI-analyzed exploit summary This repository provides a detailed technical analysis of CVE-2026-21857, a path traversal vulnerability in the Redaxo Backup addon. It includes vulnerability details, affected code snippets, and a step-by-step proof-of-concept for exploiting the issue to read arbitrary files.
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)
This repository provides a detailed technical analysis of CVE-2026-21857, a path traversal vulnerability in the Redaxo Backup addon. It includes vulnerability details, affected code snippets, and a step-by-step proof-of-concept for exploiting the issue to read arbitrary files.
References (2)
Scores
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N