CVE-2026-27734 MEDIUM

CVE-2026-27734: Beszel Vulnerable to Docker API Path Traversal via Unsanitized Container ID

Vendor Henrygd
Product beszel
Weakness CWE-22 · Path traversal
Published February 27, 2026
Last update March 2, 2026
View on NVD All CVEs

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

February 27, 2026 CVE published
March 2, 2026 Record updated