Improper input validation in Projectcapsule Capsule
CVE-2026-30963
Capsule is a multi-tenancy and policy-based framework for Kubernetes. To defend against namespace hijacking achieved through update/patch operations on namespaces, Capsule uses a webhook to validate update requests targeting namespaces. However, in Kubernetes, the namespace/finalize and namespace/status subresource APIs can also modify various fields of a namespace, including the metadata field. Prior to version 0.13.0, the webhook does not define interception rules for these subresources. As a result, if a tenant administrator has permission to modify namespace/status or namespace/finalize, they can successfully perform namespace hijacking. Version 0.13.0 fixes the issue. Another mitigation is to add two subresources (namespaces and snamespaces/status with namespace/finalize within it) to the resources list in the ValidatingWebhookConfiguration rules.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.9 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.002 (12.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.002 · change: -0.000
Affected products
- Projectcapsule Capsule — versions < 0.13.0
Weakness classification (CWE)
References
- github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6-hf35-mfjm (Exploit, Mitigation, Vendor Advisory)
- github.com/projectcapsule/capsule/releases/tag/v0.13.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-30963?
- CVE-2026-30963 is a low-severity vulnerability in Projectcapsule Capsule, classified under Improper Input Validation. CVSS score: 3.9/10. Published 2026-06-01.
- How severe is CVE-2026-30963?
- Low severity. CVSS v3 base score is 3.9 out of 10.