Nezha Monitoring: Unbounded WebSocket Streams — Resource Exhaustion DoS_CVE-2026-53522

{
    "lastseen": "",
    "description": "Nezha Monitoring is a self-hostable, lightweight, servers and websites monitoring and O&M tool. From version 1.0.0 to before version 2.2.0, the Nezha dashboard exposes two endpoints that create long-lived WebSocket streams to monitored agents: POST /api/v1/terminal \u2192 createTerminal() (terminal.go:27-67) and POST /api/v1/file \u2192 createFM() (fm.go:28-67). Both call rpc.NezhaHandlerSingleton.CreateStream(streamId, ...) which inserts a new ioStreamContext into an unbounded map[string]*ioStreamContext (s.ioStreams in io_stream.go:59-67). There is no per-user rate limit, no global semaphore, and no per-server connection cap. This issue has been patched in version 2.2.0.",
    "published": "2026-06-12T21:04:38.357Z",
    "modified": "2026-06-12T21:04:38.357Z",
    "type": "cve",
    "title": "Nezha Monitoring: Unbounded WebSocket Streams \u2014 Resource Exhaustion DoS",
    "source": "GitHub_M",
    "references": "https://github.com/nezhahq/nezha/security/advisories/GHSA-jg62-j5h6-8mpq",
    "id": "CVE-2026-53522",
    "bulletinFamily": "",
    "cwe": [
        "CWE-770"
    ],
    "cvelist": null,
    "sourceData": "nezhahq nezha >= 1.0.0, < 2.2.0",
    "sourceHref": "",
    "cvss": {
        "score": 6.5,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
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        "baseScore": 0,
        "baseSeverity": "",
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        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "nezha",
    "version": ">= 1.0.0, < 2.2.0",
    "vendor": "nezhahq",
    "ai_description": "",
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    "ai_score": 0
}