Apache CloudStack: CKS cluster in project exposes user API keys
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-200.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Apache | Apache CloudStack | 4.17.0.0 to before 4.19.3.0; 4.20.0.0 to before 4.20.1.0 | 4.19.3.0, 4.20.1.0 | Patch available | CNA |
- Apache CloudStack VendorApache Affected 4.17.0.0 to before 4.19.3.0; 4.20.0.0 to before 4.20.1.0 Fixed in 4.19.3.0, 4.20.1.0 Patch available CNA
Remediation
- Fix · CNA Apache CloudStack (Apache Software Foundation) Fixed in 4.19.3.0, 4.20.1.0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Apache CloudStack — cloudstack.apache.org/blog/cve-advisories-4.19.3.0-4.20.1.0
4 records Highest priority Priority MEDIUM 2 MEDIUM, 2 LOW
Other records, highest priority first
- TI-2025-30280 Apache CloudStack: Insecure access of user's API/Secret Keys in the same domainPriority MEDIUM 41
- TI-2025-30210 Apache CloudStack: Domain Admin can reset Admin password in Root DomainPriority MEDIUM 41
- TI-2025-21948 Apache CloudStack: Unauthorised template/ISO list access to the domain/resource adminsPriority LOW 23
Timeline
- 2026-10-02 Threatist record created from CVE-2025-26521
- 2026-10-03 Alias added: GHSA-r5jq-h47c-74h3
- 2026-10-14 EPSS moved to the 50th–90th percentile
References
More Apache Cloudstack vulnerabilities
- TI-2024-27459 Apache CloudStack: SAML Signature Exclusion CVSS 3.1HIGH 8.1
- TI-2024-25607 Apache CloudStack: Unauthenticated cluster service port leads to remote execution CVSS 3.1CRITICAL 9.8
- TI-2022-16183 Apache CloudStack SAML Single Sign-On XXE CVSS 3.1CRITICAL 9.8
- TI-2012-03843 Citrix Cloud.com CloudStack, and Apache CloudStack pre-release, allows remote attackers… CVSS 2.0HIGH 10.0
- TI-2024-26763 Apache CloudStack: Integration API service uses dynamic port when disabled CVSS 3.1CRITICAL 9.8
- TI-2016-05854 Apache CloudStack 4.1 to 4.8.1.0 and 4.9.0.0 contain an API call designed to allow a user… CVSS 3.1CRITICAL 9.8
Sources
- CVE-2025-26521 · CVE Program
- CVE-2025-26521 · NVD
- FIRST EPSS
- GHSA-r5jq-h47c-74h3 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences