CVE-2026-66797

Apache CloudStack: Unauthorised comment creation and disclosure

MEDIUM
5.4
CVSS Score
Published: August 21, 2026 at 08:21 AM UTC
Updated: October 16, 2026 at 03:10 PM UTC
1 product affected across 1 vendorCloudstack

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Severity
MEDIUM5.4
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions4.15.0.0 ≤ v < 4.20.3.14.21.0.0 ≤ v < 4.22.1.14.16.0.04.21.0.0
Affected range stops below 4.20.3.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.22.1.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

Vendor AdvisoryMailing List
Source: cverecord
https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.4MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-284

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