CRITICAL: CVE-2026-22872 (CVSS 9.1) — projectcapsule capsule

CVE: CVE-2026-22872

CVSS: 9.1 (3.1) — CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Severity: CRITICAL

Status: Critical advisory

Affected

• projectcapsule capsule

Summary

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.

Verified Sources

• NVD entry
• GitHub Advisory
• MITRE

References

• https://github.com/projectcapsule/capsule/releases/tag/v0.13.0
• https://github.com/projectcapsule/capsule/security/advisories/GHSA-qjjm-7j9w-pw72
• https://github.com/projectcapsule/capsule/security/advisories/GHSA-qjjm-7j9w-pw72

_Validated by the Lyrie Threat Intelligence Pipeline — 3 independent sources confirmed before publication. No speculation._