{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-2859","assignerOrgId":"f7d6281c-4801-44ce-ace2-493291dedb0f","state":"PUBLISHED","assignerShortName":"Checkmk","dateReserved":"2026-02-20T11:17:22.562Z","datePublished":"2026-03-13T09:40:43.743Z","dateUpdated":"2026-03-13T15:48:18.690Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Checkmk","vendor":"Checkmk GmbH","versions":[{"lessThan":"2.4.0p23","status":"affected","version":"2.4.0","versionType":"semver"},{"status":"affected","lessThan":"2.3.0p43","version":"2.3.0","versionType":"semver"},{"status":"affected","version":"2.2.0","versionType":"semver"}]}],"descriptions":[{"lang":"en","value":"Improper permission enforcement in Checkmk versions 2.4.0 before 2.4.0p23, 2.3.0 before 2.3.0p43, and 2.2.0 (EOL) allows unauthenticated users to enumerate existing hosts by observing different HTTP response codes in deploy_agent endpoint, which could lead to information disclosure."}],"impacts":[{"capecId":"CAPEC-180","descriptions":[{"lang":"en","value":"CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels"}]}],"metrics":[{"cvssV4_0":{"baseScore":6.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-204","description":"CWE-204: Observable Response Discrepancy","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"f7d6281c-4801-44ce-ace2-493291dedb0f","shortName":"Checkmk","dateUpdated":"2026-03-13T09:40:43.743Z"},"references":[{"url":"https://checkmk.com/werk/18994"}],"title":"Unauthenticated Host Enumeration via Observable Response Discrepancy on Deploy Agent Endpoint","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:*","versionStartIncluding":"2.4.0","versionEndExcluding":"2.4.0p23"},{"vulnerable":true,"criteria":"cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:*","versionStartIncluding":"2.3.0","versionEndExcluding":"2.3.0p43"},{"vulnerable":true,"criteria":"cpe:2.3:a:checkmk:checkmk:2.2.0:*:*:*:*:*:*:*"}]}]}]},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-13T15:48:12.846363Z","id":"CVE-2026-2859","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-13T15:48:18.690Z"}}]}}