CVE-2026-22872
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…
Does this matter?
Lower severity and a low EPSS score (0.68%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 6.9 MEDIUMCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.68% probability · 50th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-20, CWE-863
- Affected
- projectcapsule/capsule
- Source
- security-advisories@github.com
References
- https://github.com/projectcapsule/capsule/releases/tag/v0.13.0Product, Release Notes
- https://github.com/projectcapsule/capsule/security/advisories/GHSA-qjjm-7j9w-pw72Exploit, Vendor Advisory
- https://github.com/projectcapsule/capsule/security/advisories/GHSA-qjjm-7j9w-pw72Exploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.