{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-101088","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-09-27T20:29:07.432Z","datePublished":"2026-09-27T20:49:59.487Z","dateUpdated":"2026-09-27T20:49:59.487Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-09-27T20:49:59.487Z"},"datePublic":"2026-08-01T00:00:00.000Z","title":"Nezha before 2.3.1 Denial of Service via Concurrent Server Delete","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Time-of-check Time-of-use (TOCTOU) Race Condition","cweId":"CWE-367","type":"CWE"}]}],"affected":[{"vendor":"nezhahq","product":"nezha","defaultStatus":"unaffected","packageURL":"pkg:golang/github.com/nezhahq/nezha","versions":[{"version":"2.2.11","status":"affected","versionType":"semver","lessThan":"2.3.1"},{"version":"2.3.1","status":"unaffected","versionType":"semver"}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":5.3,"baseSeverity":"MEDIUM"}}],"references":[{"url":"https://github.com/nezhahq/nezha/security/advisories/GHSA-jx78-55p5-rwv5","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-jx78-55p5-rwv5)"},{"name":"VulnCheck Advisory: Nezha before 2.3.1 Denial of Service via Concurrent Server Delete","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/nezha-before-2.3.1-denial-of-service-via-concurrent-server-delete"}],"credits":[{"lang":"en","value":"arpitjain099","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}}}}