SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2025-55205

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…

CRITICAL 9.0EPSS 0.46%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
9.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
EPSS
0.46% probability · 40th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-863
Source
security-advisories@github.com
EPSS trend
0%3%5%26 October 2026: 0.46%26 October 202626 October 2026

EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.