Apache CloudStack: Unauthorised comment creation and disclosure (CVE-2026-66797) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-66797

Apache CloudStack: Unauthorised comment creation and disclosure

Answer in brief

CVE-2026-66797 records a Unknown severity vulnerability in Apache CloudStack: Unauthorised comment creation and disclosure. The current sources do not mark it as known exploited. The current feed maps Apache Software Foundation/Apache CloudStack (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 21, 2026Updated Aug 21, 2026Source checked Aug 21, 2026First seen by HOL Aug 21, 2026Material review Aug 21, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Apache Software Foundation/Apache CloudStack (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Apache Software Foundation/Apache CloudStackgeneric	4.16.0.0 \|\| 4.21.0.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Apache Software Foundation/Apache CloudStack.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 21, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 21, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 21, 2026

Sources and claim methodology

Source referencelists.apache.org

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.