Is CVE-2025-66171 in the CISA KEV catalog?

No. CVE-2025-66171 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2025-66171?

CVE-2025-66171 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2025-66171?

CVE-2025-66171 has an EPSS score of 0.53% (41th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2025-66171?

Upgrade cloudstack to 4.22.0.1 or later.

CVE & CISA-KEV Catalog

CVE-2025-66171

MEDIUM

6.5

CVSS v3

NVD

Description

The CloudStack Backup plugin has an improper access logic in versions 4.21.0.0 and 4.22.0.0. Anyone with authenticated user-account access in CloudStack 4.21.0.0+ environments, where this plugin is enabled and have access to specific APIs can create new VMs using backups of any other user of the environment. Backup plugin users using CloudStack 4.21.0.0+ are recommended to upgrade to CloudStack version 4.22.0.1, which fixes this issue.

CWE-359

How to fix

Remediation Available

cloudstackNVD

Affected:>= 4.21.0.0, < 4.22.0.1Fixed in:4.22.0.1CVE-2025-66171derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityNone

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Exploit Intelligence

0.53%probability of exploitation in 30 days

41stpercentile

Moderate risk: more likely to be exploited than 41% of all known CVEs.

References

Third-Party Advisory2

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-12.