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MEDIUM

Nezha before 2.3.1 Denial of Service via Concurrent Server Delete

Published Sep 27, 2026

Description

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.

Affected products

Remediation

No remediation recorded yet.

Weaknesses (1)

References (3)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner VulnCheck
Published Sep 27, 2026
Updated Sep 30, 2026
Reserved Sep 27, 2026
CISA Vulnrichment
Updated Sep 30, 2026
NVD
Status Received
Modified Sep 27, 2026
Red Hat
Severity n/a
Public date n/a
ENISA EUVD
Assigner VulnCheck
Published Sep 27, 2026
Updated Sep 30, 2026
Exploited since n/a
EUVD-2026-88023