What’s Vulnerable › Vulnerabilities

CVE-2025-55205: Capsule tenant owners with "patch namespace" permission can hijack system namespaces label

• Severity: critical (CVSS 9.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-08-18 · updated 2026-06-17
• Weakness: CWE-863

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 products

• projectcapsule capsule: before 0.10.4

References

• https://github.com/projectcapsule/capsule/commit/e1f47feade6e1695b2204407607d07c3b3994f6e
• https://github.com/projectcapsule/capsule/security/advisories/GHSA-fcpm-6mxq-m5vv

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