CVE-2026-8833

XSS in urls

State: Published
Severity: 8.5 High
Published: Jun 8, 2026
Updated: Jun 8, 2026
Reserved: May 18, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	8.5 High	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	Checkmk

Weaknesses

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Affected Products

Product	Versions
CheckmkCheckmk GmbH	2.5.0 to before 2.5.0p5Affected 2.4.0 to before 2.4.0p31Affected 2.3.0 to before 2.3.0p48Affected 2.2.0Affected

References

https://checkmk.com/werk/20002vendor-advisory

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