{"id":"CVE-2025-39663","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-39663","generatedAt":"2026-10-28T07:25:31.753Z","title":"Cross-Site Scripting (XSS) vulnerability in Checkmk's distributed monitoring allows a compromised remote site to inject malicious HTML code into service outputs in the central site.","description":"Cross-Site Scripting (XSS) vulnerability in Checkmk's distributed monitoring allows a compromised remote site to inject malicious HTML code into service outputs in the central site. Affecting Checkmk before 2.4.0p14, 2.3.0p39, 2.2.0 and 2.1.0 (eol).","published":"2025-10-30T11:15:32.000Z","lastModified":"2026-10-19T13:10:00.000Z","status":"Analyzed","sourceIdentifier":"security@checkmk.com","cvss":{"version":"4.0","score":8.5,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/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/M"},"cwe":["CWE-80","CWE-79"],"affected":["checkmk/checkmk"],"epss":{"score":0.00603,"percentile":0.48652,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://checkmk.com/werk/17998","tags":["Vendor Advisory"],"source":"security@checkmk.com"},{"url":"https://github.com/sbaresearch/advisories/tree/82fd27e4570433464c30b35150b197db9a850f4e/2025/SBA-ADV-20250729-01_Checkmk_Cross_Site_Scripting","tags":["Exploit","Third Party Advisory"],"source":"security@checkmk.com"},{"url":"http://seclists.org/fulldisclosure/2025/Nov/0","tags":["Exploit","Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/sbaresearch/advisories/tree/82fd27e4570433464c30b35150b197db9a850f4e/2025/SBA-ADV-20250729-01_Checkmk_Cross_Site_Scripting","tags":["Exploit","Third Party Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-39663","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}