CVE-2026-55636

5.7 MEDIUM 0.4% exploit odds Fix listed Auth & access Server

What it is

Capsule is a multi-tenancy and policy-based framework for Kubernetes. From 0.13.0 until 0.13.6, charts/capsule/templates/configuration.yaml configures the validating webhook with namespace/finalize instead of the Kubernetes resource name namespaces/finalize. A user with namespaces/finalize RBAC can send a PUT request to /api/v1/namespaces/{namespace}/finalize, and the singular rule never matches the plural resource, so the validating webhook is not invoked and the user can change the namespace tenant label. matchPolicy: Equivalent does not compensate because it handles API group and version equivalence rather than resource-name errors. This vulnerability is fixed in 0.13.6.

At a glance

Exploitability: Can be exploited over the network with an admin-level account, but needs a user to act. High risk of data tampering.
Exploit odds: 0.4% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-09-15 16:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-30 17:51 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.4% in the next 30 days (EPSS).
Severity: 5.7 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-09-15 16:17 UTC
Last modified: 2026-09-30 17:51 UTC
Exploit probability: 0.4% · EPSS, next 30 days
Weakness: CWE-863 · Incorrect authorization
Record status: Deferred

Attack profile CVSS 3.1 · 5.7

Attack vector: Network
Complexity: Low
Privileges needed: High
User interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: High
Availability: Low

Raw vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:H/A:L

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-55636.md and follow it. Check whether this project is affected by CVE-2026-55636. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record