Vulnerability · Published Aug 21, 2026 · Assigned by apache

CVE-2026-66797Apache CloudStack: Unauthorised comment creation and disclosure

Medium 5.4

In plain English

A medium-severity improper access control in Apache CloudStack from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.5%top 59.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
Apache Software Foundation	Apache CloudStack	4.16.0.0 – through 4.20.3.04.21.0.0 – through 4.22.1.0

Weakness: CWE-284 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

References

https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc vendor-advisory