Security Digest · Critical advisory (no CVE assigned)
GHSA-q6xx-5vr8-p898: Nezha vulnerable to cross-tenant terminal/file-manager session hijack via WebSocket stream UUID without ownership check
Summary In nezha v1.14.13–v1.14.14 and v2.0.0–v2.0.9, the WebSocket endpoints GET /ws/terminal/:id and GET /ws/file/:id authenticate the caller only by the presence of a valid stream UUID, with no ownership check tying that UUID to the user who created the stream.
CVSS 9.9 Critical GitHub-reviewed · critical
Should you act?
- Only if you depend on one of the packages below, directly or transitively, in a vulnerable version. Check your lockfile with
govulncheck ./.... - No CVE has been assigned, so it will not appear in CVE-based scanners that ignore GitHub advisories.
npm audit,pip-auditand Dependabot do read GitHub advisories.
Affected packages
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Go | github.com/nezhahq/nezha | >= 1.14.13, <= 1.14.14 | none listed |
| Go | github.com/nezhahq/nezha | >= 2.0.0, <= 2.0.9 | 2.0.10 |
Details
Summary
In nezha v1.14.13–v1.14.14 and v2.0.0–v2.0.9, the WebSocket endpoints GET /ws/terminal/:id and GET /ws/file/:id authenticate the caller only by the presence of a valid stream UUID, with no ownership check tying that UUID to the user who created the stream. Any authenticated dashboard user (including a RoleMember) who learns a live stream UUID can attach to the session and gain interactive shell access or full file-manager control on the target server — i.e. cross-tenant RCE.
This was silently fixed in commit 6661d6a (2026-05-18, shipped in v2.0.10). At submission time no public CVE/GHSA covers this fix, so operators of v1.14.x and pre-v2.0.10 v2.x deployments have no signal that they are running vulnerable code.
Details
Stream allocation — service/rpc/iostream.go (v2.0.9):
No creator is bound to the stream.
Stream attach — cmd/dashboard/controller/terminal.go (v2.0.9):
The only authorization check is GetStream(streamId) — "does this UUID exist in the in-memory map". getUid(c) is never compared against the user who called createTerminal. The same pattern is present in fmStream(c) in cmd/dashboard/controller/fm.go.
CVSS: 9.9 (v3.1) CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Sources and references
- GitHub Advisory GHSA-q6xx-5vr8-p898 github.com
- github.com github.com