CVE-2026-70656

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Source
https://cve.org/CVERecord?id=CVE-2026-70656
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-70656.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-70656
Aliases
  • GHSA-4c6j-p2cv-wf56
Published
2026-08-21T17:59:28.639Z
Modified
2026-08-23T03:53:39.563805314Z
Severity
  • 4.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
Checkmate: Regular Expression Denial of Service (ReDoS) via User-Controlled Regex in Monitor Advanced Matching
Details

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.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-1333"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/70xxx/CVE-2026-70656.json"
}
References

Affected packages

Git / github.com/bluewave-labs/checkmate

Affected ranges

Type
GIT
Repo
https://github.com/bluewave-labs/checkmate
Events
Introduced
c2170267e8d4653e04040f40f220966208f8dc21
Fixed
0df71d6356c87c747e0b796b0c34e33f2a5203fa
Fixed
adba25269c455878bf8065bc28cfe5d74e58692f
Fixed
d5ec2936ad77ab773529057b442a6eb55dd578eb
Fixed
d368ec5bd7af1cd81628c47a89d1d830cd415590
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "3.5.1"
        },
        {
            "fixed": "3.9.2"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

v3.*
v3.5.1
v3.6.1
v3.7.1
v3.9.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-70656.json"