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

Source: https://junglewise.ai/threats/cve-2026-21857-redaxo-has-path-traversal-in-backup-addon-leading-to-arbitrary  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-01-05  
License: CC BY 4.0 with a link back

CVE-2026-21857 · Severity: medium · CVSS 4 · Published 2026-01-05

Redaxo has Path Traversal in Backup Addon Leading to Arbitrary File Read

Technologies: [redaxo/source (Packagist)](https://junglewise.ai/threats/technologies/redaxo-source). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2026-21857 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-21857 being exploited in the wild.

**How severe is CVE-2026-21857?** Medium severity, with a CVSS score of 4, published 5 January 2026.

**Which products and versions are affected?** redaxo/source (Packagist) ECOSYSTEM:introduced=0,fixed=5.20.2.

**Is there a fix for CVE-2026-21857?** Yes. redaxo/source (Packagist): upgrade to 5.20.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-21857?** Check whether you run redaxo/source (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- redaxo/source (Packagist): upgrade to 5.20.2 or later

  ```sh
  composer require redaxo/source:^5.20.2
  ```


## Affected products

- redaxo/source (Packagist) ECOSYSTEM:introduced=0,fixed=5.20.2

## Identifiers

- CVE-2026-21857
- GHSA-824x-88xg-cwrv

## Related threats

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- [REDAXO Media Manager stored XSS in type name](https://junglewise.ai/threats/cve-2026-63001-redaxo-media-manager-stored-xss-in-type-name)
- [REDAXO missing CSRF protection on package update](https://junglewise.ai/threats/cve-2026-63000-redaxo-missing-csrf-protection-on-package-update)
- [REDAXO rex_list unwhitelisted ORDER BY column injection](https://junglewise.ai/threats/cve-2026-62998-redaxo-rex-list-unwhitelisted-order-by-column-injection)
- [REDAXO CMS authenticated RCE via multi-extension upload bypass](https://junglewise.ai/threats/cve-2026-53599-redaxo-cms-authenticated-rce-via-multi-extension-upload-bypass)