What is the CVSS score of EUVD-2026-28549?

EUVD-2026-28549 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of Apache CloudStack are affected by EUVD-2026-28549?

Apache CloudStack contains a remote code execution vulnerability affecting versions 4.11.0 through 4.20.2.0 and 4.21.0 through 4.22.0.0 with KVM hypervisors, enabling authenticated users to execute…

How to fix or mitigate EUVD-2026-28549?

Within 24 hours: inventory all CloudStack deployments, identify instances running versions 4.11.0-4.20.2.0 or 4.21.0-4.22.0.0 with KVM hypervisors, and document current versions. Within 7 days: upgrade to patched versions (4.20.3.0 for 4.20.x branch or 4.22.0.1 for 4.22.x branch); coordinate with infrastructure teams to schedule maintenance windows. Within 30 days: validate patch deployment across all affected systems and confirm no unsigned or suspicious templates exist in CloudStack template repositories.

Apache CloudStack EUVD-2026-28549

| CVE-2026-25077 HIGH

Code Injection (CWE-94)

2026-05-08 apache

GHSA-vhgc-6rjx-f6vv

Denial Of Service Apache Code Injection RCE

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Updated

May 10, 2026 - 15:27 vuln.today

v2 (cvss_changed)

Re-analysis Queued

May 10, 2026 - 15:22 vuln.today

cvss_changed

Severity Changed

May 10, 2026 - 15:22 NVD

MEDIUM HIGH

CVSS changed

May 10, 2026 - 15:22 NVD

6.3 (MEDIUM) 8.8 (HIGH)

Analysis Generated

May 08, 2026 - 18:23 vuln.today

CVSS changed

May 08, 2026 - 18:22 NVD

6.3 (MEDIUM)

CVE Published

May 08, 2026 - 12:21 nvd

MEDIUM 6.3

CVE Published

May 08, 2026 - 12:21 nvd

UNKNOWN (no severity yet)

DescriptionCVE.org

Account users are allowed by default to register templates to be downloaded directly to the primary storage for deploying instances using the KVM hypervisor. Due to missing file name sanitization, an attacker can register malicious templates to execute arbitrary code on the KVM hosts. This can result in the compromise of resource integrity and confidentiality, data loss, denial of service, and availability of the KVM-based infrastructure managed by CloudStack.

Users are recommended to upgrade to Apache CloudStack versions 4.20.3.0 or 4.22.0.1, or later, which fixes this issue.

AnalysisAI

Remote code execution in Apache CloudStack allows authenticated account users to execute arbitrary code on KVM hypervisor hosts by registering malicious templates with unsanitized filenames. Affects CloudStack 4.11.0 through 4.20.2.0 and 4.21.0.0 through 4.22.0.0 when using KVM hypervisors. Despite high CVSS (8.8), EPSS exploitation probability is very low (0.04%, 11th percentile) and CISA SSVC reports no active exploitation. Vendor-released patches are available in versions 4.20.3.0 and 4.22.0.1.

Technical ContextAI

Apache CloudStack is an open-source Infrastructure-as-a-Service (IaaS) cloud computing platform that manages compute, storage, and network resources. The vulnerability (CWE-94: Improper Control of Generation of Code) exists in CloudStack's template registration functionality for KVM hypervisors. When account users register templates for direct download to primary storage, the template filename parameter lacks proper sanitization. This allows injection of malicious code or path traversal sequences that execute when the template file is processed on the KVM host filesystem. The affected CPE (cpe:2.3:a:apache_software_foundation:apache_cloudstack) covers the platform's core orchestration layer that interfaces with hypervisor infrastructure. KVM (Kernel-based Virtual Machine) is a Linux hypervisor technology, and CloudStack's management of KVM hosts involves file operations that became the attack surface for this code injection vulnerability.

RemediationAI

Upgrade to Apache CloudStack version 4.20.3.0 or 4.22.0.1 (or later versions) which contain vendor-confirmed fixes for the filename sanitization vulnerability per the official Apache advisory at https://lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm. For environments unable to immediately patch, implement these compensating controls with noted trade-offs: (1) Restrict template registration permissions to trusted administrative accounts only via CloudStack role-based access control, removing this capability from general account users - this limits cloud self-service functionality but prevents untrusted users from exploiting the vulnerability. (2) Deploy file integrity monitoring on KVM hypervisor hosts to detect unauthorized file creation in primary storage paths - provides detection but not prevention, requiring active monitoring and incident response. (3) Isolate KVM management networks from untrusted account user access and enforce strict network segmentation between CloudStack management servers and hypervisor hosts - reduces attack surface but does not eliminate risk for authenticated users. All workarounds reduce functionality or require additional security tooling; vendor patching is the primary recommended remediation.