CVE-2026-9549 Details
Description
Stored 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 JavaScript into check output that executes in the browser of an admin or a user with host read permissions when they run the check on the service discovery page.
A stored cross-site scripting vulnerability has been identified in Checkmk versions 2.5.0 prior to 2.5.0p5, 2.4.0 prior to 2.4.0p31, 2.3.0 prior to 2.3.0p48, and all 2.2.0 versions. This vulnerability allows an administrator who can configure active or custom checks to inject malicious HTML or JavaScript into the check output. The injected script executes in the browser of an admin or a user with host read permissions when the check is run on the service discovery page.
Users can upgrade to Checkmk versions 2.5.0p5, 2.4.0p31, or 2.3.0p48 to address this vulnerability. Instructions for downloading the latest version can be found on the Checkmk website.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 8, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://checkmk.com/werk/17993 | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| checkmk checkmk | 2.2.0 - 2.2.0 b1 2.2.0 b2 2.2.0 b3 2.2.0 b4 2.2.0 b5 2.2.0 b6 2.2.0 b7 2.2.0 b8 2.2.0 i1 2.2.0 p1 2.2.0 p10 2.2.0 p11 2.2.0 p12 2.2.0 p13 2.2.0 p14 2.2.0 p15 2.2.0 p16 2.2.0 p17 2.2.0 p18 2.2.0 p19 2.2.0 p2 2.2.0 p20 2.2.0 p21 2.2.0 p22 2.2.0 p23 2.2.0 p24 2.2.0 p25 2.2.0 p26 2.2.0 p27 2.2.0 p28 2.2.0 p29 2.2.0 p3 2.2.0 p30 2.2.0 p31 2.2.0 p32 2.2.0 p33 2.2.0 p34 2.2.0 p35 2.2.0 p36 2.2.0 p37 2.2.0 p38 2.2.0 p39 2.2.0 p4 2.2.0 p40 2.2.0 p41 2.2.0 p42 2.2.0 p43 2.2.0 p44 2.2.0 p45 2.2.0 p46 2.2.0 p47 2.2.0 p5 2.2.0 p6 2.2.0 p7 2.2.0 p8 2.2.0 p9 2.3.0 - 2.3.0 b1 2.3.0 b2 2.3.0 b3 2.3.0 b4 2.3.0 b5 2.3.0 b6 2.3.0 p1 2.3.0 p10 2.3.0 p11 2.3.0 p12 2.3.0 p13 2.3.0 p14 2.3.0 p15 2.3.0 p16 2.3.0 p17 2.3.0 p18 2.3.0 p19 2.3.0 p2 2.3.0 p20 2.3.0 p21 2.3.0 p22 2.3.0 p23 2.3.0 p24 2.3.0 p25 2.3.0 p26 2.3.0 p27 2.3.0 p28 2.3.0 p29 2.3.0 p3 2.3.0 p30 2.3.0 p31 2.3.0 p32 2.3.0 p33 2.3.0 p34 2.3.0 p35 2.3.0 p36 2.3.0 p37 2.3.0 p38 2.3.0 p39 2.3.0 p4 2.3.0 p40 2.3.0 p41 2.3.0 p42 2.3.0 p43 2.3.0 p44 2.3.0 p45 2.3.0 p46 2.3.0 p47 2.3.0 p5 2.3.0 p6 2.3.0 p7 2.3.0 p8 2.3.0 p9 2.4.0 2.4.0 - 2.4.0 b1 2.4.0 b2 2.4.0 b3 2.4.0 b4 2.4.0 b5 2.4.0 b6 2.4.0 p1 2.4.0 p10 2.4.0 p11 2.4.0 p12 2.4.0 p13 2.4.0 p14 2.4.0 p15 2.4.0 p16 2.4.0 p17 2.4.0 p18 2.4.0 p19 2.4.0 p2 2.4.0 p20 2.4.0 p21 2.4.0 p22 2.4.0 p23 2.4.0 p24 2.4.0 p25 2.4.0 p26 2.4.0 p27 2.4.0 p28 2.4.0 p29 2.4.0 p3 2.4.0 p30 2.4.0 p4 2.4.0 p5 2.4.0 p6 2.4.0 p7 2.4.0 p8 2.4.0 p9 2.5.0 - 2.5.0 b1 2.5.0 b2 2.5.0 b3 2.5.0 p1 2.5.0 p2 2.5.0 p3 2.5.0 p4 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 8, 2026 | Initial Analysis | [email protected] |
| Jun 8, 2026 | New CVE Received | [email protected] |