Vulnerability · Published Sep 3, 2026 · Assigned by VulnCheck

CVE-2026-85390Checkmate through 3.11.0 Missing Authorization on Maintenance Window, Notification, and Check Deletion Routes

High 7.1

In plain English

A high-severity missing authorization in Checkmate from bluewave-labs. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).

Severity (CVSS 3.1)7.1High

Exploit odds (30 days)0.5%top 58.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Checkmate through 3.11.0 omits the isAllowed role guard middleware on maintenance-window, notification, and check-deletion routes, allowing read-only users to perform administrative actions. Attackers with user-role sessions can create arbitrary maintenance windows to silence alerts, modify notification channels, and delete monitor check history to erase incident evidence.

Affected products (as reported)

Vendor	Product	Versions
bluewave-labs	Checkmate	0 – through 3.11.0

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

References

GitHub Issue #3916 issue-tracking
https://github.com/bluewave-labs/Checkmate product
https://github.com/bluewave-labs/Checkmate/blob/v3.11.0/server/src/api/routes/maintenanceWindowRoutes.ts technical-description
https://github.com/bluewave-labs/Checkmate/blob/v3.11.0/server/src/api/routes/notificationRoutes.ts technical-description
https://github.com/bluewave-labs/Checkmate/blob/v3.11.0/server/src/api/routes/checkRoutes.ts technical-description
VulnCheck Advisory: Checkmate through 3.11.0 Missing Authorization on Maintenance Window, Notification, and Check Deletion Routes third-party-advisory