CVE-2026-30963Public exploitNetwork attack vector

Namespace hijacking via unvalidated subresource metadata

Published Jun 1, 2026 · Updated Jun 1, 2026

Improper input validation in Project Capsule's Capsule before 0.13.0 allows remote authenticated users to hijack Kubernetes namespaces. The validating webhook omits namespace/status and namespace/finalize from its interception rules, so PATCH requests can replace namespace ownerReferences without Capsule's ownership check. Exploitation requires tenant-administrator RBAC permission to modify either subresource and reassigns a namespace to an attacker-controlled tenant.

CVSS severity3.9
Low
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Project Capsule's Capsule before 0.13.0 allows remote authenticated users to hijack Kubernetes namespaces. The validating webhook omits namespace/status and namespace/finalize from its interception rules, so PATCH requests can replace namespace ownerReferences without Capsule's ownership check. Exploitation requires tenant-administrator RBAC permission to modify either subresource and reassigns a namespace to an attacker-controlled tenant.

The record

CVE
CVE-2026-30963
Published
Jun 1, 2026
Updated
Jun 1, 2026
Vendor
Project Capsule
Product
Capsule
Classifications
CWE-20, T1068
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.13.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Project Capsule · Capsuleversion=< 0.13.0

Published CVSS scores

2.7NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
3.9GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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