CVE-2026-61399Network attack vector

Cross-site scripting via unescaped lock-user output

Published Aug 21, 2026 · Updated Aug 21, 2026

Cross-site scripting in Apache CloudStack 4.20.0.0 through 4.20.3.0 and 4.21.0.0 through 4.22.1.0 allows attackers to run script. The lock-user UI path fails to encode or escape output, but Apache has not identified the affected field or rendering operation. Exploitation requires remote authenticated users to hold high privileges and induce victim interaction; successful script runs in another UI context.

CVSS severity4.8
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Apache CloudStack 4.20.0.0 through 4.20.3.0 and 4.21.0.0 through 4.22.1.0 allows attackers to run script. The lock-user UI path fails to encode or escape output, but Apache has not identified the affected field or rendering operation. Exploitation requires remote authenticated users to hold high privileges and induce victim interaction; successful script runs in another UI context.

The record

CVE
CVE-2026-61399
Published
Aug 21, 2026
Updated
Aug 21, 2026
Vendor
The Apache Software Foundation
Product
Apache CloudStack
Classifications
CWE-116
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.20.0.0 <=4.20.3.0
  2. Affected versionversion=4.21.0.0 <=4.22.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache CloudStackversion=4.20.0.0 <=4.20.3.0; version=4.21.0.0 <=4.22.1.0

Published CVSS scores

4.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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