CVE-2026-66721

UNRATEDCVSS · not yet scoredTrending — 3 sources updated this week
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EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: —CVSS v2: —Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Missing authorization issue for domain admins in CloudStack's host tags listing functionality.

Domain Admins, by default, have permission to call the listHostTags API, but the API returns host tags for every host in the environment without domain scoping. It should instead be restricted to only the hosts dedicated to that admin's domain.

This issue affects Apache CloudStack: from 4.12.0.0 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.

CVSS v3
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EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
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EPSS PROB
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EPSS %ILE
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KEV
Not listed

Published

August 21, 2026

Last Modified

August 21, 2026

References (1)

Vendor Advisories for CVE-2026-66721(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 3× in last 7d / 3× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-21 09:16 UTCNVD update
  2. 2026-08-21 08:40 UTCEG score recompute
  3. 2026-08-21 08:39 UTCMITRE cvelistV5first tracked

Frequently asked(3)

What is CVE-2026-66721?
CVE-2026-66721 is a publicly disclosed vulnerability published on August 21, 2026. Missing authorization issue for domain admins in CloudStack's host tags listing functionality. Domain Admins, by default, have permission to call the listHostTags API, but the API returns host tags for every host in the environment without domain scoping. It should instead be restricted to only the…
When was CVE-2026-66721 disclosed?
CVE-2026-66721 was first published in the National Vulnerability Database on August 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
How do I remediate CVE-2026-66721?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66721, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-66721

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