RCE in Apache Cloudstack

CVE-2026-61400

Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in Apache CloudStack's run and get diagnostics functionality for the system VMs and virtual routers. An authenticated user holding the permissions required to invoke either `getDiagnosticsData` or `runDiagnostics` can achieve arbitrary command execution on the system VM and/or Virtual Router instances, with commands running as root (or as the diagnostics-process user, at minimum). This represents a full compromise of the affected instance and, depending on network segmentation, may provide a foothold for lateral movement within the CloudStack-managed infrastructure, including access to guest network traffic handled by the compromised Virtual Router. The getDiagnosticsData and runDiagnostics APIs are restricted to only Admin role accounts by default. This issue affects Apache CloudStack: from 4.20.0.0 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.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.029 (86.5th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 86.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-61400: rose from 0.015 to 0.029.

EPSS over last 30 days · oldest: 0.015 · newest: 0.029 · change: +0.014

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-61400?
CVE-2026-61400 is a high-severity vulnerability in Apache Cloudstack, classified under Command Injection. CVSS score: 8.8/10. Published 2026-08-21.
How severe is CVE-2026-61400?
High severity. CVSS v3 base score is 8.8 out of 10.