CVE-2026-53522

Medium

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.

SeverityMedium
CVSS6.5
Exploit probability—
ProductGithub.com/nezhahq/nezha
PublishedJun 12, 2026
First seenJun 12, 2026

How to fix

Update
  • github.com/nezhahq/nezha2.2.0 or later

Affected products

ProductAffected versionsFixed in
github.com/nezhahq/nezhaGo1.0.0 ≤ v < 2.2.0, 1.0.0 ≤ v2.2.0

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