CVE-2026-55636 json
Capsule: Incomplete fix of CVE-2026-30963: singular/plural typo leaves namespaces/finalize unprotected
published 2026-06-17 4 mo ago modified 2026-09-30 39 d ago also EUVD-2026-78670 , GHSA-gwxr-7h77-7777 , GO-2026-5406
- cvss
- 5.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 32%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go github.com/projectcapsule/capsule 0.13.6
- clastix capsule 0.13.6
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 54 d ago
Exploit prediction
0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:H/A:L |
| GitHub | 3.1 | 5.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:H/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/projectcapsule/capsule | >=0.13.0, <0.13.6 |
0.13.6 |
Affected products
- projectcapsule capsule
Classification
- Weakness
-
- CWE-863 Incorrect Authorization
References
- github.com /projectcapsule/capsule/pull/1966
- github.com /projectcapsule/capsule/commit/af2f37793e789b2301da8ed8dfb52ab60affebb6
-
github.com
/projectcapsule/capsule/security/advisories/GHSA-gwxr-7h77-7777
web, advisory
- github.com /projectcapsule/capsule/releases/tag/v0.13.6
-
github.com
/projectcapsule/capsule
package
Sources
- CVE List CVE-2026-55636
- GitHub Advisory GHSA-gwxr-7h77-7777
- NVD CVE-2026-55636
- OSV GO-2026-5406
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.