CVE-2026-70656 - Checkmate: Regular Expression Denial of Service (ReDoS) via User-Controlled Regex in Monitor Advanced Matching
Brief
CVE ID : CVE-2026-70656
Published : Aug. 21, 2026, 6:16 p. m.
- 53 minutes ago
Description : 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.
- 1 until 3.
- 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.
- 2.