{"id":"CVE-2026-9549","state":"PUBLISHED","title":"Fix XSS in service discovery active check output","description":"Stored cross-site scripting in the service discovery active check output in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can configure active or custom checks to inject malicious HTML or JavaScript into check output that executes in the browser of an admin or a user with host read permissions when they run the check on the service discovery page.","publishedAt":"2026-06-08T12:07:12.356Z","updatedAt":"2026-06-08T13:02:20.748Z","severity":{"score":4.8,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","source":"Checkmk"},"assigner":"Checkmk","products":["Checkmk GmbH Checkmk"],"affected":[{"vendor":"Checkmk GmbH","product":"Checkmk","defaultStatus":"unaffected","versions":[{"version":"2.5.0","status":"affected","lessThan":"2.5.0p5","versionType":"semver"},{"version":"2.4.0","status":"affected","lessThan":"2.4.0p31","versionType":"semver"},{"version":"2.3.0","status":"affected","lessThan":"2.3.0p48","versionType":"semver"},{"version":"2.2.0","status":"affected","versionType":"semver"}]}],"references":["https://checkmk.com/werk/17993"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:13:52.441Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/9xxx/CVE-2026-9549.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-9549","state":"PUBLISHED","datePublished":"2026-06-08T12:07:12.356Z","dateUpdated":"2026-06-08T13:02:20.748Z","assignerShortName":"Checkmk","assignerOrgId":"f7d6281c-4801-44ce-ace2-493291dedb0f","dateReserved":"2026-05-26T07:04:28.900Z"},"containers":{"cna":{"title":"Fix XSS in service discovery active check output","descriptions":[{"lang":"en","value":"Stored cross-site scripting in the service discovery active check output in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can configure active or custom checks to inject malicious HTML or JavaScript into check output that executes in the browser of an admin or a user with host read permissions when they run the check on the service discovery page."}],"affected":[{"vendor":"Checkmk GmbH","product":"Checkmk","defaultStatus":"unaffected","versions":[{"version":"2.5.0","status":"affected","lessThan":"2.5.0p5","versionType":"semver"},{"version":"2.4.0","status":"affected","lessThan":"2.4.0p31","versionType":"semver"},{"version":"2.3.0","status":"affected","lessThan":"2.3.0p48","versionType":"semver"},{"version":"2.2.0","status":"affected","versionType":"semver"}]}],"references":[{"url":"https://checkmk.com/werk/17993","tags":["vendor-advisory"]}],"metrics":[{"cvssV4_0":{"baseScore":4.8,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"Checkmk","orgId":"f7d6281c-4801-44ce-ace2-493291dedb0f","dateUpdated":"2026-06-08T12:07:12.356Z"},"impacts":[{"capecId":"CAPEC-592","descriptions":[{"lang":"en","value":"CAPEC-592: Stored XSS"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:*","versionStartIncluding":"2.5.0","versionEndExcluding":"2.5.0p5"},{"vulnerable":true,"criteria":"cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:*","versionStartIncluding":"2.4.0","versionEndExcluding":"2.4.0p31"},{"vulnerable":true,"criteria":"cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:*","versionStartIncluding":"2.3.0","versionEndExcluding":"2.3.0p48"},{"vulnerable":true,"criteria":"cpe:2.3:a:checkmk:checkmk:2.2.0:*:*:*:*:*:*:*"}]}]}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-08T13:02:10.372370Z","id":"CVE-2026-9549","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-08T13:02:20.748Z"}}]}}}