How severe is CVE-2026-66721?

CVE-2026-66721 has a CVSS 3.x base score of 2.7, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-66721 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-66721?

CVE-2026-66721 affects Apache Cloudstack. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-66721?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-66721 published?

CVE-2026-66721 was published on 2026-08-21 and last updated on 2026-08-27.

CVE-2026-66721

CVE-2026-66721 is a low-severity vulnerability in Apache Cloudstack with a CVSS 3.x base score of 2.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-862.

Key facts

Severity: Low (CVSS 3.x base score 2.7)
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Apache Cloudstack
Published: 2026-08-21
Last modified: 2026-08-27

Description

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.

Frequently asked questions

What is CVE-2026-66721?: 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.
How severe is CVE-2026-66721?: CVE-2026-66721 has a CVSS 3.x base score of 2.7, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-66721 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-66721?: CVE-2026-66721 affects Apache Cloudstack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-66721?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-66721 published?: CVE-2026-66721 was published on 2026-08-21 and last updated on 2026-08-27.

References

https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc

Affected products (1)

cpe:2.3:a:apache:cloudstack:*:*:*:*:*:*:*:*

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