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CVE-2026-66721: Missing authorization issue for domain admins in CloudStack's host tags listing functionality. Domain Admi

25
Routine
LOW 2.7WATCHLISTUPGRADE

CVE-2026-66721 is a low-severity flaw (CVSS 2.7) affecting cloudstack. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Missing authorization issue for domain admins in CloudStack's host tags listing functionality. Domain Admins, by default, have permission to call the listHostTags API, but the API returns host tags for every host in the environment without domain scoping. It should instead be restricted to only the hosts dedicated to that admin's domain. This issue affects Apache CloudStack: from 4.12.0.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.

Why this priority

  • On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score2.7 (Low)
Attack vectorNetwork (remote)
Attack complexityLow
Privileges neededHigh
User interactionNone
EPSS exploit chance0.5% (top 59%)
CISA exploited listNo
WeaknessCWE-862
Published2026-08-21
Last modified2026-10-16
Publisher (CNA): Apache Software Foundation · Vendor: apache

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Last updated 2026-10-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

apache cloudstack UPGRADE
Affected: >= 4.12.0.0 and < 4.20.3.1 · >= 4.21.0.0 and < 4.22.1.1
Fixed in: 4.20.3.1, 4.22.1.1
Safe to downgrade to: a release before 4.12.0.0
1. Check installed version
apt-cache policy cloudstack || rpm -q cloudstack || cloudstack --version
2. UPGRADE to 4.20.3.1 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade cloudstack
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade cloudstack
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 4.12.0.0 (Debian / Ubuntu)
apt-cache madison cloudstack sudo apt install cloudstack=<VERSION_BEFORE_4.12.0.0> sudo apt-mark hold cloudstack
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list cloudstack sudo dnf downgrade cloudstack-<VERSION_BEFORE_4.12.0.0> sudo dnf versionlock add cloudstack
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-66721?

cloudstack: upgrade to 4.20.3.1, 4.22.1.1. Exact commands for each OS are on this page.

Is CVE-2026-66721 being exploited?

CVE-2026-66721 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-66721 affect?

CVE-2026-66721 affects cloudstack. Severity is low (CVSS 2.7). Missing authorization issue for domain admins in CloudStack's host tags listing functionality. Domain Admins, by default, have permission to call the listHostTags API, but the API returns host tags for every host in the environment with

How urgent is CVE-2026-66721?

Priority 25/100. On your watchlist

Related CVEs

References

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