Vulnerability · Published Aug 18, 2025 · Assigned by GitHub_M
CVE-2025-55205Capsule tenant owners with "patch namespace" permission can hijack system namespaces label
Critical 9.1
In plain English
A critical-severity incorrect authorization in capsule from projectcapsule. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% 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. A namespace label injection vulnerability in Capsule v0.10.3 and earlier allows authenticated tenant users to inject arbitrary labels into system namespaces (kube-system, default, capsule-system), bypassing multi-tenant isolation and potentially accessing cross-tenant resources through TenantResource selectors. This vulnerability enables privilege escalation and violates the fundamental security boundaries that Capsule is designed to enforce. This vulnerability is fixed in 0.10.4.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/projectcapsule/capsule | 0.10.4 | GHSA-fcpm-6mxq-m5vv |
| Go | github.com/projectcapsule/capsule | 0.10.4 | GO-2025-3893 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| projectcapsule | capsule | < 0.10.4 |
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H