CVE-2026-8833Medium· 5.4▾ SunlitImproper 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…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 29.7 · likelihood 0 · exploitation 0
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Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.2%
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.
checkmk = 2.2.0checkmk = 2.3.0checkmk = 2.4.0checkmk = 2.5.0Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-9549Medium· 4.8Stored 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 Java…
CVE-2026-8078Medium· 4.8Stored cross-site scripting in the global settings change log in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can change global settings to store malicious HTML or JavaScript in changelog mes…
CVE-2026-7186Medium· 5.4Stored cross-site scripting in the URL dashboard widget in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows a user with dashboard editing permissions to store a URL with a dangerous URI scheme such as javascript: tha…
CVE-2026-20915Medium· 5.4Stored 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 …
CVE-2026-33276Medium· 5.4Stored cross-site scripting (XSS) in Checkmk 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create hosts or services to execute arbitrary JavaScript in the browsers of other users performing searches in the Uni…
CVE-2021-40906Medium· 6.1CheckMK Raw Edition software (versions 1.5.0 to 1.6.0) does not sanitise the input of a web service parameter that is in an unauthenticated zone