CVE-2025-56534Public exploitNetwork attack vector

Stored XSS via custom authenticator payload

Published Apr 29, 2026 · Updated Apr 29, 2026

Stored XSS in OpenNebula Sunstone 6.10.0.1 allows remote attackers to execute scripts through a crafted custom authenticator payload. The published materials identify opennebula-sunstone and supply an HTML event-handler payload, but do not disclose the input field or code-level storage and rendering path. Exploitation requires the custom authenticator driver and a user to view the persisted payload in Sunstone; script execution remains in that browser context, with no reported service interruption.

CVSS severity6.1
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in OpenNebula Sunstone 6.10.0.1 allows remote attackers to execute scripts through a crafted custom authenticator payload. The published materials identify opennebula-sunstone and supply an HTML event-handler payload, but do not disclose the input field or code-level storage and rendering path. Exploitation requires the custom authenticator driver and a user to view the persisted payload in Sunstone; script execution remains in that browser context, with no reported service interruption.

The record

CVE
CVE-2025-56534
Published
Apr 29, 2026
Updated
Apr 29, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 29, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

Public exploit references

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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