What is CVE-2025-66171?

CVE-2025-66171 is a medium-severity vulnerability in Apache Cloudstack, classified under Exposure of Private Personal Information to an Unauthorized Actor. CVSS score: 6.5/10. Published 2026-05-08.

How severe is CVE-2025-66171?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Apache Cloudstack

CVE-2025-66171

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…

EPSS: 0.000 (3.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Apache Cloudstack
Apache Software Foundation Cloudstack — versions 4.21.0.0

Weakness classification (CWE)

CWE-359 — Exposure of Private Personal Information to an Unauthorized Actor

References

security@apache.org (vendor-advisory, Mailing List, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2025-66171?: CVE-2025-66171 is a medium-severity vulnerability in Apache Cloudstack, classified under Exposure of Private Personal Information to an Unauthorized Actor. CVSS score: 6.5/10. Published 2026-05-08.
How severe is CVE-2025-66171?: Medium severity. CVSS v3 base score is 6.5 out of 10.