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. From 3.3.0 until 3.9.2, enabling the global showURL setting causes the unauthenticated GET /api/v1/status-page/:url endpoint to return complete monitor objects from server/src/controllers/statusPageController.ts. The response includes the secret field used by HttpProvider.ts as an HTTP Authorization credential, even though BaseStatusPage.tsx does not display that value, allowing visitors to extract credentials from the JSON response and use them against monitored services. This issue is fixed in version 3.9.2.
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. From 3.5.1 until 3.9.2, an authenticated admin or superadmin can set matchMethod to regex and place a malicious expression in the expectedValue field for advanced HTTP monitor matching. server/src/api/validation/monitorValidation.ts accepts the expression, and server/src/service/network/AdvancedMatcher.ts synchronously evaluates it against an attacker-controlled HTTP response body on the Node.js main event loop without a timeout or worker isolation, allowing catastrophic backtracking to freeze API endpoints, monitor checks, and WebSocket connections for all users. This issue is fixed in version 3.9.2.
CVE-2026-55241 is a high-severity vulnerability in bluewave-labs Checkmate prior to version 3.9.1. It involves uncontrolled resource consumption via the public POST /api/v1/auth/register endpoint, which processes multipart profile image uploads without limits on file size, count, or MIME type. An unauthenticated attacker can submit concurrent oversized files that are buffered in memory before registration validation, leading to memory exhaustion and potential backend crashes or destabilization. This issue is fixed in version 3.9.1.
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.
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. Prior to version 3.4.0, an unauthenticated information disclosure vulnerability exists in the GET /api/v1/status-page/:url endpoint. The endpoint does not enforce authentication or verify whether a status page is published before returning full status page details. As a result, unpublished status pages and their associated internal data are accessible to any unauthenticated user via direct API requests. This issue has been patched in version 3.4.0.