CVE-2026-27734
Path Traversal in Beszel API Allows Docker Endpoint Exposure
Publication date: 2026-02-27
Last updated on: 2026-03-04
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| beszel | beszel | to 0.18.2 (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. |
Attack-Flow Graph
AI Powered Q&A
How can this vulnerability impact me? :
An attacker who is authenticated, including those with readonly roles, can exploit this vulnerability to traverse to arbitrary Docker API endpoints on the agent hosts. This unauthorized access can expose sensitive infrastructure details, potentially revealing critical information about the monitored environment. Such exposure can lead to further attacks or compromise of the infrastructure.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade Beszel to version 0.18.4 or later, where the issue has been fixed.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
Can you explain this vulnerability to me?
This vulnerability exists in the Beszel server monitoring platform prior to version 0.18.2. The issue is that the authenticated API endpoints GET /api/beszel/containers/logs and GET /api/beszel/containers/info accept a user-supplied "container" query parameter without validating it. The agent then uses this raw value to construct Docker Engine API URLs without proper escaping. Because Go's http.Client does not sanitize "../" sequences in URL paths sent over unix sockets, an authenticated user, even with readonly role, can perform directory traversal to access arbitrary Docker API endpoints on the agent hosts. This can expose sensitive infrastructure details. The issue was fixed in version 0.18.4.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know