CVE-2026-70656

{"id": "CVE-2026-70656", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-70656", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-21T18:06:46.856684Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "HIGH", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.2}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "bluewave-labs", "product": "Checkmate", "versions": [{"status": "affected", "version": ">= 3.5.1, < 3.9.2"}]}]}], "published": "2026-08-21T18:16:50.277", "references": [{"url": "https://github.com/bluewave-labs/Checkmate/commit/0df71d6356c87c747e0b796b0c34e33f2a5203fa", "source": "security-advisories@github.com"}, {"url": "https://github.com/bluewave-labs/Checkmate/commit/adba25269c455878bf8065bc28cfe5d74e58692f", "source": "security-advisories@github.com"}, {"url": "https://github.com/bluewave-labs/Checkmate/commit/d5ec2936ad77ab773529057b442a6eb55dd578eb", "source": "security-advisories@github.com"}, {"url": "https://github.com/bluewave-labs/Checkmate/releases/tag/v3.9.2", "source": "security-advisories@github.com"}, {"url": "https://github.com/bluewave-labs/Checkmate/security/advisories/GHSA-4c6j-p2cv-wf56", "source": "security-advisories@github.com"}, {"url": "https://github.com/bluewave-labs/Checkmate/security/advisories/GHSA-4c6j-p2cv-wf56", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-1333"}]}], "descriptions": [{"lang": "en", "value": "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 3.5.1 until 3.9.2, 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 3.9.2."}], "lastModified": "2026-08-21T19:17:50.190", "sourceIdentifier": "security-advisories@github.com"}