Vulnerability in Beszel
CVE-2026-40077
Beszel is a server monitoring platform. Prior to 0.18.7, some API endpoints in the Beszel hub accept a user-supplied system ID and proceed without further checks that the user should have access to that system. As a result, any authenticated user can access these routes for any system if they know the system's ID. System IDs are random 15 character alphanumeric strings, and are not exposed to all users. However, it is theoretically possible for an authenticated user to enumerate a valid system ID via web API. To use the containers endpoints, the user would also need to enumerate a container ID, which is 12 digit hexadecimal string. This vulnerability is fixed in 0.18.7.
EPSS: 0.002 (12.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N.
Affected products
- Beszel
- Henrygd Beszel — versions < 0.18.7
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-40077?
- CVE-2026-40077 is a low-severity vulnerability in Beszel, classified under Incomplete List of Disallowed Inputs. CVSS score: 3.5/10. Published 2026-04-09.
- How severe is CVE-2026-40077?
- Low severity. CVSS v3 base score is 3.5 out of 10.