Stored cross-site scripting in Pending Changes sidebar
Summary
| CVE | CVE-2026-20915 |
|---|---|
| State | PUBLISHED |
| Assigner | Checkmk |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-31 15:16:11 UTC |
| Updated | 2026-04-02 12:06:00 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 8.5 HIGH from [email protected]
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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.000430000 probability, percentile 0.132140000 (date 2026-04-01)
Problem Types: CWE-79 | CWE-79 CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 8.5 | HIGH | 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/C... |
| 4.0 | CNA | DECLARED | 8.5 | HIGH | 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 |
| 3.1 | [email protected] | Primary | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
HighUser Interaction
PassiveConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
LowSub Availability
NoneCVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
RequiredScope
ChangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Checkmk GmbH | Checkmk | affected 2.5.0b1 2.5.0b2 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| checkmk.com/werk/19526 | [email protected] | checkmk.com | Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.