GHSA-WHFQ-93MC-CV6G
Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-09 09:31Instances deployed via the Proxmox extension allow unauthorized access to instances belonging to other tenants.
This issue affects Apache CloudStack: from 4.21.0.0 through 4.22.0.0.
The Proxmox extension for CloudStack improperly uses a user-editable instance setting, proxmox_vmid, to associate CloudStack instances with Proxmox virtual machines. Because this value is not restricted or validated against tenant ownership and Proxmox VM IDs are predictable, a non-privileged attacker can modify the setting to reference a VM belonging to another account. This allows unauthorized cross-tenant access and enables full control over the targeted VM, including starting, stopping, and destroying the virtual machine.
Users are recommended to upgrade to version 4.22.0.1, which fixes this issue.
As a workaround for the existing installations, editing of the proxmox_vmid instance detail by users can be prevented by adding this detail name to the global configuration parameter - user.vm.denied.details.
{
"affected": [],
"aliases": [
"CVE-2026-25199"
],
"database_specific": {
"cwe_ids": [
"CWE-200"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-08T13:16:36Z",
"severity": "CRITICAL"
},
"details": "Instances deployed via the Proxmox extension allow unauthorized access to instances belonging to other tenants.\n\n\n\n\nThis issue affects Apache CloudStack: from 4.21.0.0 through 4.22.0.0.\n\n\n\n\nThe Proxmox extension for CloudStack improperly uses a user-editable instance setting, proxmox_vmid, to associate CloudStack instances with Proxmox virtual machines. Because this value is not restricted or validated against tenant ownership and Proxmox VM IDs are predictable, a non-privileged attacker can modify the setting to reference a VM belonging to another account. This allows unauthorized cross-tenant access and enables full control over the targeted VM, including starting, stopping, and destroying the virtual machine.\n\n\n\n\nUsers are recommended to upgrade to version 4.22.0.1, which fixes this issue.\n\n\n\n\nAs a workaround for the existing installations,\u00a0editing of the proxmox_vmid instance detail by users can be prevented by adding this detail name to the global configuration parameter - user.vm.denied.details.",
"id": "GHSA-whfq-93mc-cv6g",
"modified": "2026-05-09T09:31:44Z",
"published": "2026-05-08T15:31:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-25199"
},
{
"type": "WEB",
"url": "https://lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2026/05/09/7"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.