---
id: CVE-2026-61672
title: Capsule is a multi-tenancy and policy-based framework for Kubernetes
summary: >-
  Capsule is a multi-tenancy and policy-based framework for Kubernetes. Prior to
  0.13.7, ForbiddenListSpec.ExactMatch in pkg/api/forbidden_list.go sorts denied
  metadata keys case-insensitively and then uses sort.SearchStrings, which
  assume…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N'
cwe:
  - CWE-697
  - CWE-863
vendor: projectcapsule
product: capsule
affected:
  - capsule < 0.13.7
patched:
  - github.com/projectcapsule/capsule 0.13.7
published: '2026-09-18'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:25:27.050'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61672'
references:
  - url: >-
      https://github.com/projectcapsule/capsule/commit/755cef54bf4a1bc56d6692130132bc70755bef46
    label: security-advisories@github.com
  - url: 'https://github.com/projectcapsule/capsule/pull/1982'
    label: security-advisories@github.com
  - url: 'https://github.com/projectcapsule/capsule/releases/tag/v0.13.7'
    label: security-advisories@github.com
  - url: >-
      https://github.com/projectcapsule/capsule/security/advisories/GHSA-gjw4-3v3v-rqxg
    label: security-advisories@github.com
  - url: >-
      https://github.com/projectcapsule/capsule/security/advisories/GHSA-gjw4-3v3v-rqxg
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-gjw4-3v3v-rqxg'
  - url: 'https://github.com/projectcapsule/capsule'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - go
  - osv
epss: 0.00334
epssPercentile: 0.23994
aliases:
  - GHSA-gjw4-3v3v-rqxg
ecosystem: go
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-22T14:56:05.830592Z'
ingestedAt: '2026-09-18T16:45:41.406Z'
---

## Overview

Capsule is a multi-tenancy and policy-based framework for Kubernetes. Prior to 0.13.7, ForbiddenListSpec.ExactMatch in pkg/api/forbidden_list.go sorts denied metadata keys case-insensitively and then uses sort.SearchStrings, which assumes byte-order sorting. When an administrator's forbidden list mixes capitalized and lowercase keys or otherwise has different case-insensitive and byte ordering, the binary search can return false for a key that is present. An authenticated tenant owner can then pass the missed key through api.ValidateForbidden and bypass configured namespace, Service, or delegated node metadata restrictions, potentially influencing cluster policies, network exposure, or scheduling outside the tenant boundary. Uniformly lowercase lists whose two orderings coincide are not affected. This issue is fixed in version 0.13.7.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-61672)

Affected packages:

- `github.com/projectcapsule/capsule <= 0.13.6`

Patched in:

- `github.com/projectcapsule/capsule 0.13.7`

Source: https://github.com/advisories/GHSA-gjw4-3v3v-rqxg