CVE-2026-85390 Checkmate through 3.11.0 Missing Authorization on Maintenance Window, Notification, and Check Deletion Routes
Read-only users can perform administrative actions like deleting checks and modifying notifications due to missing authorization guards.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-85390?
CVE-2026-85390 is a high-severity missing authorization vulnerability in bluewave-labs Checkmate, published on 3 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-862
Which versions are affected by CVE-2026-85390?
How do I fix CVE-2026-85390?
No fix has been published for CVE-2026-85390 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-85390 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85390 exists.
Sources
Also known as GHSA-8cvg-rxfw-4pf6.