{"id":"CVE-2026-20915","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-20915","generatedAt":"2026-10-28T08:36:45.906Z","title":"Stored cross-site scripting (XSS) in Checkmk version 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create pending changes to inject malicious JavaScript into the Pending Changes sidebar, which will execute in the browsers of…","description":"Stored cross-site scripting (XSS) in Checkmk version 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create pending changes to inject malicious JavaScript into the Pending Changes sidebar, which will execute in the browsers of other users viewing the sidebar.","published":"2026-03-31T15:16:12.000Z","lastModified":"2026-07-25T10:10:00.000Z","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:L/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-79"],"affected":["checkmk/checkmk"],"epss":{"score":0.00147,"percentile":0.03858,"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 (0.15%). 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/19526","tags":["Vendor Advisory"],"source":"security@checkmk.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-20915","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."}