CVE-2025-26521 Apache CloudStack: CKS cluster in project exposes user API keys

High 8.1 Published 10 Jun 2025 Updated 26 Feb 2026

Project members can access the creator's API keys from Kubernetes cluster secrets, allowing account impersonation and resource compromise.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-26521?

CVE-2025-26521 is a high-severity vulnerability in Apache Cloudstack, published on 10 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

When an Apache CloudStack user-account creates a CKS-based Kubernetes cluster in a project, the API key and the secret key of the 'kubeadmin' user of the caller account are used to create the secret config in the CKS-based Kubernetes cluster. A member of the project who can access the CKS-based Kubernetes cluster, can also access the API key and secret key of the 'kubeadmin' user of the CKS cluster's creator's account. An attacker who's a member of the project can exploit this to impersonate and perform privileged actions that can result in complete compromise of the confidentiality, integrity, and availability of resources owned by the creator's account.

CKS users are recommended to upgrade to version 4.19.3.0 or 4.20.1.0, which fixes this issue.Updating Existing Kubernetes Clusters in ProjectsA service account should be created for each project to provide limited access specifically for Kubernetes cluster providers and autoscaling. Follow the steps below to create a new service account, update the secret inside the cluster, and regenerate existing API and service keys:1. Create a New Service AccountCreate a new account using the role "Project Kubernetes Service Role" with the following details:

Account Name kubeadmin-<FIRST_EIGHT_CHARACTERS_OF_PROJECT_ID> First Name Kubernetes Last Name Service User Account Type 0 (Normal User) Role ID <ID_OF_SERVICE_ROLE>

2. Add the Service Account to the ProjectAdd this account to the project where the Kubernetes cluster(s) are hosted. 3. Generate API and Secret KeysGenerate API Key and Secret Key for the default user of this account. 4. Update the CloudStack Secret in the Kubernetes ClusterCreate a temporary file `/tmp/cloud-config` with the following data: api-url = <API_URL> # For example: <MS_URL>/client/api api-key = <SERVICE_USER_API_KEY> secret-key = <SERVICE_USER_SECRET_KEY> project-id = <PROJECT_ID>

Delete the existing secret using kubectl and Kubernetes cluster config: ./kubectl --kubeconfig kube.conf -n kube-system delete secret cloudstack-secret

Create a new secret using kubectl and Kubernetes cluster config: ./kubectl --kubeconfig kube.conf -n kube-system create secret generic cloudstack-secret --from-file=/tmp/cloud-config

Remove the temporary file: rm /tmp/cloud-config5. Regenerate API and Secret KeysRegenerate the API and secret keys for the original user account that was used to create the Kubernetes cluster.

Weakness: CWE-200

Which versions are affected by CVE-2025-26521?

It affects 1 product.

Products include Apache Cloudstack.

How do I fix CVE-2025-26521?

No fix has been published for CVE-2025-26521 yet. Limit exposure of the affected software until one is available.

Is CVE-2025-26521 being exploited?

There is no known exploitation of CVE-2025-26521 in the wild and no public exploit code.

All Apache Cloudstack vulnerabilities

Sources

Also known as GHSA-r5jq-h47c-74h3.