CVE-2026-25199

CVE-2026-25199 is a critical-severity vulnerability in Apache Cloudstack with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Description

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.

Frequently asked questions

What is CVE-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, 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.
How severe is CVE-2026-25199?
CVE-2026-25199 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-25199 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-25199?
CVE-2026-25199 affects Apache Cloudstack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-25199?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-25199 have an EU (EUVD) identifier?
Yes. CVE-2026-25199 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28550.
When was CVE-2026-25199 published?
CVE-2026-25199 was published on 2026-05-08 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Apache Cloudstack

All CVEs affecting Apache Cloudstack →

Other CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) vulnerabilities

Browse all CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) vulnerabilities →