6.5

CVE-2025-66171: apache software foundation apache cloudstack

CVSS: 6.5v3.1MediumAnalyzed
Published 08-05-2026Last modified 09-05-2026
Open JSON

Vulnerability summary

CVE-2025-66171 is a medium (CVSS 6.5) vulnerability in apache software foundation apache cloudstack. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.5% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.53%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 08-05-2026
    PublishedVulnerability first disclosed.
  2. 09-05-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.53%

Chance of exploitation in the next 30 days

Percentile

44%

Versus all other CVEs

30-day change

0.00 pp

From 0.53% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.53%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Apache1 product
Apache software foundation1 product

2 vendors · 2 products

References

2 links