---
id: CVE-2026-50112
title: >-
  SSRF via Metalink Mirror URL Resolution:


  An authenticated tenant can register a template pointing to an
  attacker-controlled metalink file containing internal targets
summary: >-
  SSRF via Metalink Mirror URL Resolution:


  An authenticated tenant can register a template pointing to an
  attacker-controlled metalink file containing internal targets. The Secondary
  Storage VM will retrieve the data and persist it as a t…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-78
  - CWE-918
vendor: apache
product: cloudstack
affected:
  - 'cloudstack >= 4.14.0.0, < 4.20.3.1'
  - 'cloudstack >= 4.21.0.0, < 4.22.1.1'
patched:
  - cloudstack 4.22.1.1
published: '2026-08-21'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:10:00.103'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-50112'
references:
  - url: 'https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc'
    label: security@apache.org
tags:
  - nvd
epss: 0.00723
epssPercentile: 0.53793
ingestedAt: '2026-10-27T18:52:09.887Z'
---

## Overview

SSRF via Metalink Mirror URL Resolution:

An authenticated tenant can register a template pointing to an attacker-controlled metalink file containing internal targets. The Secondary Storage VM will retrieve the data and persist it as a template file, which can later be downloaded through normal APIs.

RCE on KVM hypervisor via NFS, Metalink files with/without Direct Downloads:

An authenticated CloudStack tenant holding the default User role can execute arbitrary shell commands as root on the KVM hypervisor host that runs other tenants' VMs. This is cross-tenant root on the underlying compute, reachable via the public CloudStack API.


When a User registers a VM template with directDownload=true and a URL pointing to a .metalink file, the management server fetches the metalink XML and dispatches download to the KVM agent. Inner URLs inside the metalink XML are never re-validated against the scheme allowlist.


These issues affect Apache CloudStack: from 4.14.0.0 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.

## Affected

- `cloudstack >= 4.14.0.0, < 4.20.3.1`
- `cloudstack >= 4.21.0.0, < 4.22.1.1`

## Remediation

Upgrade past the affected range:

- `cloudstack 4.22.1.1`