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Vulnerability record · CVE-2026-66797 · published 21 August 2026

CVE-2026-66797: Apache cloudstack improper access control vulnerability

Apache · Cloudstack

Improper access control in CloudStack's annotation functionality allows unauthorized comment creation and disclosure. The addAnnotation and listAnnotation APIs perform an ownership check when an entity's UUID is specified, but fail to honor its result correctly. This lets any authenticated user write annotations to, and disclose existing annotations/comments on, an entity they don't own by simply supplying its UUID. This issue affects Apache CloudStack: from 4.15.0.0 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.

5.4 CVSS 3.1 Medium EPSS 0.46% · top 62.6% CWE-284 · Improper access control
5.4CVSS 3.1 base score
0.46%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References
27 Aug 2026Last modified by NVD

Description

Improper access control in CloudStack's annotation functionality allows unauthorized comment creation and disclosure. The addAnnotation and listAnnotation APIs perform an ownership check when an entity's UUID is specified, but fail to honor its result correctly. This lets any authenticated user write annotations to, and disclose existing annotations/comments on, an entity they don't own by simply supplying its UUID. This issue affects Apache CloudStack: from 4.15.0.0 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:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc Mailing ListVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-66797), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.