{"api_version":"1","generated_at":"2026-09-28T00:03:39+00:00","cve":"CVE-2026-101088","urls":{"html":"https://cve.report/CVE-2026-101088","api":"https://cve.report/api/cve/CVE-2026-101088.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-101088","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-101088"},"summary":{"title":"Nezha before 2.3.1 Denial of Service via Concurrent Server Delete","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.","state":"PUBLISHED","assigner":"VulnCheck","published_at":"2026-09-27 21:17:02","updated_at":"2026-09-27 21:17:02"},"problem_types":["CWE-367","CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition"],"metrics":[{"version":"4.0","source":"disclosure@vulncheck.com","type":"Secondary","score":"6","severity":"MEDIUM","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","data":{"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":6,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}},{"version":"4.0","source":"CNA","type":"CVSS","score":"6","severity":"MEDIUM","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","data":{"attackComplexity":"HIGH","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6,"baseSeverity":"MEDIUM","privilegesRequired":"LOW","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE"}},{"version":"3.1","source":"disclosure@vulncheck.com","type":"Primary","score":"5.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"5.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","data":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://github.com/nezhahq/nezha/security/advisories/GHSA-jx78-55p5-rwv5","name":"https://github.com/nezhahq/nezha/security/advisories/GHSA-jx78-55p5-rwv5","refsource":"disclosure@vulncheck.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.vulncheck.com/advisories/nezha-before-2.3.1-denial-of-service-via-concurrent-server-delete","name":"https://www.vulncheck.com/advisories/nezha-before-2.3.1-denial-of-service-via-concurrent-server-delete","refsource":"disclosure@vulncheck.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-101088","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101088","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"nezhahq","product":"nezha","version":"affected 2.2.11 2.3.1 semver","platforms":[]},{"source":"CNA","vendor":"nezhahq","product":"nezha","version":"unaffected 2.3.1 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"arpitjain099","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","packageURL":"pkg:golang/github.com/nezhahq/nezha","product":"nezha","vendor":"nezhahq","versions":[{"lessThan":"2.3.1","status":"affected","version":"2.2.11","versionType":"semver"},{"status":"unaffected","version":"2.3.1","versionType":"semver"}]}],"credits":[{"lang":"en","type":"reporter","value":"arpitjain099"}],"datePublic":"2026-08-01T00:00:00.000Z","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."}],"metrics":[{"cvssV4_0":{"attackComplexity":"HIGH","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6,"baseSeverity":"MEDIUM","privilegesRequired":"LOW","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE"},"format":"CVSS"},{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-367","description":"Time-of-check Time-of-use (TOCTOU) Race Condition","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-27T20:49:59.487Z","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck"},"references":[{"name":"GitHub Security Advisory (GHSA-jx78-55p5-rwv5)","tags":["vendor-advisory"],"url":"https://github.com/nezhahq/nezha/security/advisories/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"}],"title":"Nezha before 2.3.1 Denial of Service via Concurrent Server Delete","x_generator":{"engine":"vulncheck-endgame"}}},"cveMetadata":{"assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","assignerShortName":"VulnCheck","cveId":"CVE-2026-101088","datePublished":"2026-09-27T20:49:59.487Z","dateReserved":"2026-09-27T20:29:07.432Z","dateUpdated":"2026-09-27T20:49:59.487Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-27 21:17:02","lastModifiedDate":"2026-09-27 21:17:02","problem_types":["CWE-367","CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition"],"metrics":{"cvssMetricV40":[{"source":"disclosure@vulncheck.com","type":"Secondary","cvssData":{"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":6,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"disclosure@vulncheck.com","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.6,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"101088","Ordinal":"1","Title":"Nezha before 2.3.1 Denial of Service via Concurrent Server Delet","CVE":"CVE-2026-101088","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"101088","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Nezha before 2.3.1 Denial of Service via Concurrent Server Delet"}]}}}