Apache Cloudstack
CVE-2026-66797
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.
What this means for your business
- It affects Apache Cloudstack. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 18% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Apache Cloudstack, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Fastnexa security experts
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Scoring
- CVSS
- 5.4 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N- Weakness
- CWE-284
- Assigned by
- security@apache.org
Dates
- Published
- 2026-08-21
- Last modified
- 2026-08-27
- Sources
- NVD
Affected products
- Apache Cloudstack4.15.0.0 - 4.20.3.1, 4.21.0.0 - 4.22.1.1
As listed in the NVD configuration data. Not a statement about your estate.