SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-31836

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.

HIGH 8.1EPSS 0.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS
0.29% probability · 22th percentile
CISA KEV
Not listed
Weakness
CWE-269, CWE-285
Affected
bluewavelabs/checkmate
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.