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CVE PROGRAM SOURCE RECORD6.5 Medium

CVE-2026-53522

Nezha Monitoring: Unbounded WebSocket Streams — Resource Exhaustion DoS

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 → 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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

nezhahq nezha

  • >= 1.0.0, < 2.2.0affected

References