CVE-2026-61672
Capsule: Tenant owner bypasses Capsule's forbidden namespace/service/node label and annotation enforcement
Description
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.
INFO
Published Date :
Sept. 18, 2026, 5:16 p.m.
Last Modified :
Sept. 18, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Capsule to version 0.13.7.
- Verify metadata restrictions are enforced.
- Ensure forbidden lists use consistent casing.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-61672.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-61672 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-61672
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-61672 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-61672 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N Added CWE CWE-697 Added CWE CWE-863 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/61xxx/CVE-2026-61672.json">CVE-2026-61672</a> Added Reference https://github.com/projectcapsule/capsule/commit/755cef54bf4a1bc56d6692130132bc70755bef46 Added Reference https://github.com/projectcapsule/capsule/pull/1982 Added Reference https://github.com/projectcapsule/capsule/releases/tag/v0.13.7 Added Reference https://github.com/projectcapsule/capsule/security/advisories/GHSA-gjw4-3v3v-rqxg