Checkmate through 3.11.0 Missing Authorization on Maintenance Window, Notification, and Check Deletion Routes
Priority MEDIUM 64CWE-862Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-862.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00486 42nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| bluewave-labs | Checkmate | up to 3.11.0 | — | No fix listed | CNA |
- Checkmate Vendorbluewave-labs Affected up to 3.11.0 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-85390
- 2026-10-03 Alias added: GHSA-8cvg-rxfw-4pf6
References
Other 5
- GitHub Issue #3916
- https://github.com/bluewave-labs/Checkmate
- https://github.com/bluewave-labs/Checkmate/blob/v3.11.0/server/src/api/routes/maintenanceWindowRoutes.ts
- https://github.com/bluewave-labs/Checkmate/blob/v3.11.0/server/src/api/routes/notificationRoutes.ts
- https://github.com/bluewave-labs/Checkmate/blob/v3.11.0/server/src/api/routes/checkRoutes.ts
More bluewave-labs vulnerabilities
- TI-2026-39916 Checkmate: Pre-auth Denial of Service via File Upload on Registration CVSS 3.1HIGH 7.5
- TI-2026-24389 Mass Assignment Privilege Escalation in Checkmate CVSS 3.1HIGH 8.1
- TI-2026-23658 Checkmate: Unauthenticated Access to Unpublished Status Page CVSS 3.1MEDIUM 5.3
- TI-2026-49357 Checkmate: Regular Expression Denial of Service (ReDoS) via User-Controlled Regex in Monitor Advanced Matching CVSS 3.1MEDIUM 4.9
- TI-2026-50184 Checkmate: Sensitive Bearer Token Exposure via Public Status Pages When showURL Setting is Enabled CVSS 3.1HIGH 7.5
- TI-2026-50845 bluewave-labs Checkmate - User Enumeration via Differential HTTP Response in Password Recovery CVSS 3.1MEDIUM 5.3
Sources
- CVE-2026-85390 · CVE Program
- CVE-2026-85390 · NVD
- FIRST EPSS
- GHSA-8cvg-rxfw-4pf6 · GitHub Advisory Database · CC BY 4.0
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