CVE-2026-85390

CVE-2026-85390

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.

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L.

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-85390?
CVE-2026-85390 is a high-severity vulnerability, classified under Missing Authorization. CVSS score: 7.1/10. Published 2026-09-03.
How severe is CVE-2026-85390?
High severity. CVSS v3 base score is 7.1 out of 10.