Mass Assignment Privilege Escalation in Checkmate

published 2026-03-20 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-13744

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits: 0; none known

Checkmate is an open-source, self-hosted tool designed to track and monitor server hardware, uptime, response times, and incidents in real-time with beautiful visualizations. In versions from 3.5.1 and prior, a mass assignment vulnerability in Checkmate's user profile update endpoint allows any authenticated user to escalate their privileges to superadmin, bypassing all role-based access controls. An attacker can modify their user role to gain complete administrative access to the application, including the ability to view all users, modify critical configurations, and access sensitive system data. At time of publication, there are no publicly available patches.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 7 mo ago (2026-03-20)

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/bluewave-labs/Checkmate/security/advisories/GHSA-6368-x7wr-wpm2 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected products

bluewave-labs Checkmate

Classification

Weakness

CWE-285 Improper Authorization
CWE-269 Improper Privilege Management

References

github.com /bluewave-labs/Checkmate/security/advisories/GHSA-6368-x7wr-wpm2
exploit, vendor-advisory

Sources

CVE List CVE-2026-31836
NVD CVE-2026-31836

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary