CVE-2026-27734
Beszel Vulnerable to Docker API Path Traversal via Unsanitized Container ID
Description
Beszel is a server monitoring platform. Prior to version 0.18.2, the hub's authenticated API endpoints GET /api/beszel/containers/logs and GET /api/beszel/containers/info pass the user-supplied "container" query parameter to the agent without validation. The agent constructs Docker Engine API URLs using fmt.Sprintf with the raw value instead of url.PathEscape(). Since Go's http.Client does not sanitize `../` sequences from URL paths sent over unix sockets, an authenticated user (including readonly role) can traverse to arbitrary Docker API endpoints on agent hosts, exposing sensitive infrastructure details. Version 0.18.4 fixes the issue.
INFO
Published Date :
Feb. 27, 2026, 8:21 p.m.
Last Modified :
March 4, 2026, 4:50 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update Beszel to version 0.18.4 or later.
- Validate user input for API endpoints.
- Sanitize query parameters for agent communication.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-27734.
| URL | Resource |
|---|---|
| https://github.com/henrygd/beszel/releases/tag/v0.18.4 | Product Release Notes |
| https://github.com/henrygd/beszel/security/advisories/GHSA-phwh-4f42-gwf3 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-27734 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-27734
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-27734 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-27734 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 04, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:beszel:beszel:*:*:*:*:*:*:*:* versions up to (excluding) 0.18.2 Added Reference Type GitHub, Inc.: https://github.com/henrygd/beszel/releases/tag/v0.18.4 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/henrygd/beszel/security/advisories/GHSA-phwh-4f42-gwf3 Types: Exploit, Vendor Advisory -
New CVE Received by [email protected]
Feb. 27, 2026
Action Type Old Value New Value Added Description Beszel is a server monitoring platform. Prior to version 0.18.2, the hub's authenticated API endpoints GET /api/beszel/containers/logs and GET /api/beszel/containers/info pass the user-supplied "container" query parameter to the agent without validation. The agent constructs Docker Engine API URLs using fmt.Sprintf with the raw value instead of url.PathEscape(). Since Go's http.Client does not sanitize `../` sequences from URL paths sent over unix sockets, an authenticated user (including readonly role) can traverse to arbitrary Docker API endpoints on agent hosts, exposing sensitive infrastructure details. Version 0.18.4 fixes the issue. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-22 Added Reference https://github.com/henrygd/beszel/releases/tag/v0.18.4 Added Reference https://github.com/henrygd/beszel/security/advisories/GHSA-phwh-4f42-gwf3