EUVD-2026-63838
GHSA-4rrq-73x5-wj26
Severity by source
AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Network-based UI XSS requiring low-privilege attacker account and admin UI interaction; scope changes to victim browser session with limited C/I impact and no availability impact.
Primary rating from Vendor (apache).
CVSS VectorVendor: apache
Lifecycle Timeline
2DescriptionCVE.org
Improper Encoding or Escaping of Output vulnerability in Apache CloudStack's UI while using Lock User Functionality.
This issue affects Apache CloudStack: from 4.20.0.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.0.
Users are recommended to upgrade to version 4.20.3.1 or 4.22.1.1 or later, which fixes the issue.
AnalysisAI
Improper output encoding in Apache CloudStack's management UI exposes administrators to cross-site scripting (XSS) when using the Lock User functionality across versions 4.20.0.0-4.20.3.0 and 4.21.0.0-4.22.1.0. A low-privilege user can embed a malicious script payload in a user-controlled field; when an administrator invokes the Lock User workflow, the CloudStack UI renders the payload without proper HTML or JavaScript escaping, executing it in the admin's browser session. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires two preconditions: first, the attacker must hold a valid (low-privilege) user account in the target Apache CloudStack deployment to inject a payload into a user-controlled attribute; second, a CloudStack administrator must actively invoke the Lock User workflow against that account, triggering the unescaped rendering. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | No CVSS vector was provided by the Apache reporter, so all metric assessments are independently inferred. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | Upgrade to Apache CloudStack 4.20.3.1 (for deployments on the 4.20.x branch) or 4.22.1.1 (for deployments on the 4.21.x/4.22.x branch) or any later release, as confirmed by the Apache advisory at https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-116 – Improper Encoding or Escaping of Output
View allSame technique Information Disclosure
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External POC / Exploit Code
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