{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-8833","assignerOrgId":"f7d6281c-4801-44ce-ace2-493291dedb0f","state":"PUBLISHED","assignerShortName":"Checkmk","dateReserved":"2026-05-18T14:06:43.958Z","datePublished":"2026-06-08T12:06:51.267Z","dateUpdated":"2026-06-08T13:02:45.679Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Checkmk","vendor":"Checkmk GmbH","versions":[{"lessThan":"2.5.0p5","status":"affected","version":"2.5.0","versionType":"semver"},{"lessThan":"2.4.0p31","status":"affected","version":"2.4.0","versionType":"semver"},{"lessThan":"2.3.0p48","status":"affected","version":"2.3.0","versionType":"semver"},{"status":"affected","version":"2.2.0","versionType":"semver"}]}],"credits":[{"lang":"en","type":"reporter","value":"Arvato Systems Offensive Security"}],"descriptions":[{"lang":"en","value":"Improper neutralization of HTML-encoded characters in the URL validation function in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an authenticated user to bypass URL validation and inject malicious URLs such as javascript: URIs, resulting in cross-site scripting when another user interacts with the crafted link."}],"impacts":[{"capecId":"CAPEC-63","descriptions":[{"lang":"en","value":"CAPEC-63: Cross-Site Scripting (XSS)"}]}],"metrics":[{"cvssV4_0":{"baseScore":8.5,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/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":{"orgId":"f7d6281c-4801-44ce-ace2-493291dedb0f","shortName":"Checkmk","dateUpdated":"2026-06-08T12:06:51.267Z"},"references":[{"url":"https://checkmk.com/werk/20002","tags":["vendor-advisory"]}],"title":"XSS in urls","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":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-08T13:02:39.672018Z","id":"CVE-2026-8833","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-06-08T13:02:45.679Z"}}]}}