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Vulnerabilities

Vulnerability · CVE-2026-25199

Instances deployed via the Proxmox extension allow unauthorized access to instances belonging to other tenants.

Published May 8, 2026 · catalog updated Jun 17, 2026 · Instances deployed via the

Check if you run it

No confirmed exploitation is on record for CVE-2026-25199. EPSS is 0.50%. Act only if a listed version of Instances deployed via the is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Instances deployed via the).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.50%
Remediation
Advisory link
Affected products
cpe apache/cloudstack

Instances 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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe apache/cloudstackversion unspecified

How to fix CVE-2026-25199

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-25199. EPSS is 0.50%. Act only if a listed version of Instances deployed via the is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-200: Exposure of Sensitive Information. EPSS 0.50%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 8, 2026 · NIST NVD

    Detected

    Instances 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 ag

  2. Jun 17, 2026 · NIST NVD

    Updated

    Instances 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 ag

Sources

  • CVE.orgVulnerability recordCVE-2026-25199

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-25199

    30-day exploitation probability 0.5%

    first.org
  • NIST NVDVulnerability recordCVE-2026-25199

    Instances 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, pro

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.