Vulnerability · Published Sep 27, 2026 · Assigned by VulnCheck

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

Medium 5.3

In plain English

A medium-severity security flaw in nezha from nezhahq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.2%top 92.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
nezhahq	nezha	2.2.11 – before 2.3.1

Weakness: CWE-367 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

References

GitHub Security Advisory (GHSA-jx78-55p5-rwv5) vendor-advisory
VulnCheck Advisory: Nezha before 2.3.1 Denial of Service via Concurrent Server Delete third-party-advisory