{"id":"CVE-2026-8833","title":"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 j…","summary":"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 j…","severity":"medium","cvss":5.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","cwe":["CWE-79"],"vendor":"checkmk","product":"checkmk","affected":["checkmk = 2.2.0","checkmk = 2.3.0","checkmk = 2.4.0","checkmk = 2.5.0"],"published":"2026-06-08","updated":"2026-10-06","sourceUpdated":"2026-10-06T22:10:00.247","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-8833","references":[{"url":"https://checkmk.com/werk/20002","label":"security@checkmk.com"}],"tags":["nvd"],"epss":0.00238,"epssPercentile":0.13584,"ingestedAt":"2026-10-06T22:23:15.934Z","slug":"CVE-2026-8833","body":"## Overview\n\nImproper 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.\n\n## Affected\n\n- `checkmk = 2.2.0`\n- `checkmk = 2.3.0`\n- `checkmk = 2.4.0`\n- `checkmk = 2.5.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}