CVE-2026-55636Capsule: Incomplete fix of CVE-2026-30963: singular/plural typo leaves namespaces/finalize unprotected
- 5.7MediumCVSS base score
- 0.39%Exploitation in 30 daysEPSS · top 67% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By GitHub_M
- 3 months later
· 3 months later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:H/A:L |
| NVDNVD · Deferred | 3.1 | Medium5.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:H/A:L |
- EPSS (exploitation in 30 days)
- 0.39% · top 67% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.7.
Affected products
- affected >= 0.13.0, < 0.13.6
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/projectcapsule/capsuleGHSA-gwxr-7h77-7777 (opens in a new tab)
References
References4
- https://github.com/projectcapsule/capsule/security/advisories/GHSA-gwxr-7h77-7777 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/projectcapsule/capsule/pull/1966 (opens in a new tab)x_refsource_MISC
- https://github.com/projectcapsule/capsule/commit/af2f37793e789b2301da8ed8dfb52ab60affebb6 (opens in a new tab)x_refsource_MISC
- https://github.com/projectcapsule/capsule/releases/tag/v0.13.6 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-78670 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-gwxr-7h77-7777 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-55636)Record last updated .