CVE-2026-120046

Nezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect endpoint. When the dashboard_host setting is empty, /api/v1/oauth2/{provider} reflects the attacker-supplied Host header into the redirect_uri. An attacker can steal the victim's authorization code and take over the account.

Nezha from 2.2.5 before 2.3.15 contains an information disclosure vulnerability that allows authenticated users to retrieve third-party credentials because listDDNS omits WebhookURL and WebhookRequestBody redaction. Admins or PATs with nezha:ddns:read scope can call GET /api/v1/ddns to read cleartext tokens.

Nezha from 1.7.0 before 2.3.15 contains an information disclosure vulnerability that allows authenticated members to enumerate other tenants' server IDs through differential responses. Attackers can sweep sequential IDs against getServerConfig and setServerConfig to map other users' servers.

Nezha from 2.1.0 before 2.3.15 contains a host header injection vulnerability in mintTransferTool that builds fs.download_url and fs.upload_url transfer URLs from the unvalidated Host header. Attackers who control the Host header seen on a victim's MCP request can redirect file uploads or capture one-time download tokens.

Nezha 1.0.0 before 2.3.15 contains a memory exhaustion vulnerability in the dashboard file manager WebSocket endpoint because fmStream never calls SetReadLimit, leaving message size unbounded. Authenticated users with file manager scopes can send one oversized binary message to /api/v1/ws/file/:id, triggering an OOM kill.

Nezha from 2.0.13 before 2.3.15 contains a resource exhaustion vulnerability that allows authenticated users to open unbounded concurrent connections to the /api/v1/ws/transfer WebSocket endpoint. Attackers can hold thousands of subscriptions created by ServerTransferClass.Subscribe, exhausting file descriptors, memory, and goroutines.

Nezha from 1.8.0 before 2.3.13 contains a lock-order inversion in UpdateGroup and DeleteGroup that allows authenticated non-admin users to deadlock the alerting subsystem. Attackers can concurrently call the notification-group and batch-delete endpoints with oversized id lists to widen the race and close an ABBA cycle, permanently killing alert delivery until restart.

Nezha before 2.2.7 contains an information disclosure vulnerability in the GET /api/v1/profile endpoint that returns the bcrypt-hashed password field of authenticated users. Attackers can extract password hashes and perform offline cracking attacks without rate limiting or audit trail constraints.

Nezha is a server and website monitoring tool. In versions >= 2.2.11 and < 2.3.1, the service sentinel worker (service/singleton/servicesentinel.go) contains an incomplete fix for a previously reported nil dereference denial of service (GHSA-qjpp-gffx-2wm9). The 2026-07-21 fix re-validated the service lifecycle under serviceResponseDataStoreLock but reused an already-captured, now stale reporter pointer and never re-validated the server, and that lock does not guard ServerShared. An authenticated user with the member role who owns an agent can issue a concurrent server delete (POST /api/v1/batch-delete/server) for their own server to win the race window, causing the worker to dereference a missing entry in the server list snapshot. Because the sentinel workers and the gRPC server have no recover()/recovery interceptor, the resulting panic is unrecovered and crashes the entire instance. This is fixed in version 2.3.1.

Nezha versions 2.0.10 through 2.3.2 use a restricted HTTP client to validate user-configurable notification and DDNS webhook URLs, but the denylist did not cover IPv6 transition ranges — specifically the 6to4 prefix 2002::/16 and the local-use IPv4/IPv6 translation prefix 64:ff9b:1::/48. Because such addresses satisfy Go's netip.Addr.IsGlobalUnicast check, the URL validator accepted them. An authenticated user able to configure a webhook may be able to cause the dashboard to issue requests to an otherwise restricted IPv6 endpoint, but only where the dashboard's network provides unusual or non-standards-compliant routing for these transition ranges; no direct path to an IPv4 metadata, loopback, or private-network HTTP request has been demonstrated. The issue is fixed in version 2.3.3 (commit d1fcde8e), which blocks both prefixes.