Vulnerability · Published Jun 1, 2026 · Assigned by GitHub_M
CVE-2026-22872Capsule TenantResource RawItems Cluster-Scoped Resource Creation Vulnerability
Medium 6.9
In plain English
A medium-severity improper input validation in capsule from projectcapsule. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Capsule is a multi-tenancy and policy-based framework for Kubernetes. The Capsule Controller runs with cluster-admin privileges. Although the TenantResource RawItems processing logic forcibly sets the namespace, this is ineffective for cluster-scoped resources. Prior to version 0.13.0, tenant administrators can leverage the Controller's elevated privileges to create cluster-scoped resources (such as ClusterRole and ValidatingWebhookConfiguration) that they cannot create directly, achieving cross-tenant privilege escalation and cluster-level attacks. The attack vector has a few limiting factors. This attack requires Tenant Owner privileges and requires Capsule Controller running with cluster-admin privileges (default configuration). Additionally, some clusters may have additional admission controllers blocking malicious resources. Version 0.13.0 patches this issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/projectcapsule/capsule | 0.13.0 | GO-2026-5584 |
| Go | github.com/projectcapsule/capsule | 0.13.0 | GHSA-qjjm-7j9w-pw72 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| projectcapsule | capsule | < 0.13.0 |
Weakness: CWE-20, CWE-863 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:P
References
- https://github.com/projectcapsule/capsule/security/advisories/GHSA-qjjm-7j9w-pw72 x_refsource_CONFIRM
- https://github.com/projectcapsule/capsule/releases/tag/v0.13.0 x_refsource_MISC