CVE-2026-21857
Path Traversal in REDAXO Backup Addon Allows Arbitrary File Access
Publication date: 2026-01-07
Last updated on: 2026-01-07
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| redaxo | redaxo | to 5.20.2 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-22 | The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. |
| CWE-24 | The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize "../" sequences that can resolve to a location that is outside of that directory. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the REDAXO content management system's Backup addon prior to version 5.20.2. Authenticated users with backup permissions can exploit a path traversal flaw in the file export functionality by manipulating the EXPDIR POST parameter. The addon does not properly validate this parameter against the allowed directories, allowing attackers to include arbitrary readable files from within the webroot in the backup archive by using relative paths like '../' or absolute paths inside the document root.
How can this vulnerability impact me? :
This vulnerability can allow an attacker with backup permissions to read arbitrary files within the webroot, potentially exposing sensitive information stored on the server. This could lead to unauthorized disclosure of confidential data, which may compromise the security and privacy of the system and its users.
What immediate steps should I take to mitigate this vulnerability?
Upgrade REDAXO to version 5.20.2 or later, as this version fixes the path traversal vulnerability in the Backup addon. Additionally, restrict backup permissions to trusted authenticated users only until the upgrade is applied.