Nezha Monitoring: Unbounded WebSocket Streams — Resource Exhaustion DoS
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 → createTerminal() (terminal.go:27-67) and POST /api/v1/file → 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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-53522
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 13:29 UTC · Revision 1
Source evidence
Nezha Monitoring: Unbounded WebSocket Streams — Resource Exhaustion DoS
core-osv · Original sourcePublished 12 Jun 2026, 21:04 UTC
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 → createTerminal() (terminal.go:27-67) and POST /api/v1/file → 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.
osv:CVE-2026-53522
Complete source record
{
"id": "965d886b321f31f2f234181df8aaa90f1481101b2100c21208aa01f5e277ac11",
"url": "https://osv.dev/vulnerability/CVE-2026-53522",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Nezha Monitoring: Unbounded WebSocket Streams — Resource Exhaustion DoS",
"summary": "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 → createTerminal() (terminal.go:27-67) and POST /api/v1/file → 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.",
"evidence": "osv:CVE-2026-53522",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-53522",
"aliases": [
"CVE-2026-53522",
"GHSA-jg62-j5h6-8mpq",
"GO-2026-5831"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/nezhahq/nezha",
"type": "GIT",
"events": [
{
"introduced": "1772de7c5ece397164189d5fac375809353683c8"
},
{
"fixed": "46325e8d895eb1823d357b5d32768c784a48aaef"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "1.0.0"
},
{
"fixed": "2.2.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"introduced": "0"
},
{
"fixed": "2.2.0"
}
],
"source": "DESCRIPTION"
}
]
}
}
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53522.json"
}
}
],
"modified": "2026-10-28T02:30:28.974457577Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53522.json",
"https://github.com/nezhahq/nezha/security/advisories/GHSA-jg62-j5h6-8mpq",
"https://nvd.nist.gov/vuln/detail/CVE-2026-53522"
],
"provider_metadata": {
"cwe_ids": [
"CWE-770"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53522.json"
}
},
"related_cves": [
{
"value": "CVE-2026-53522",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 495880,
"published_at": "2026-06-12T21:04:38.357+00:00"
}