---
id: CVE-2026-101088
title: Nezha is a server and website monitoring tool
summary: >-
  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 (…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-367
vendor: nezhahq
product: nezha
affected:
  - nezha >= 2.2.11 < 2.3.1
published: '2026-09-27'
updated: '2026-09-27'
sourceUpdated: '2026-09-27T21:17:02.727'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101088'
references:
  - url: 'https://github.com/nezhahq/nezha/security/advisories/GHSA-jx78-55p5-rwv5'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/nezha-before-2.3.1-denial-of-service-via-concurrent-server-delete
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-27T20:58:01.539Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.