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OpenAdvisories
Medium · 6.5 CVE-2026-27734 EUVD-2026-9053GHSA-phwh-4f42-gwf3GO-2026-4571

Beszel Vulnerable to Docker API Path Traversal via Unsanitized Container ID

Published Feb 27, 2026 · Updated Mar 2, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
henrygd beszel < 0.18.4 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1
openSUSE Leap 15.6 govulncheck-vulndb 0.0.20260317T205859-150000.1.152.1 SUSE-SU-2026:1042-1
ReleasePackageFixed inAdvisory
Alpine v3.23 beszel 0.18.7-r0 —

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/henrygd/beszel < 0.18.4 0.18.4 GHSA-phwh-4f42-gwf3

Advisories 2

References