CVE-2025-55205 json
Capsule tenant owners with "patch namespace" permission can hijack system namespaces label
published 2025-08-18 14 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-25141 , GHSA-fcpm-6mxq-m5vv , GO-2025-3893
- cvss
- 9.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 42%
- public exploits
- 0
- none known
Summary
Capsule is a multi-tenancy and policy-based framework for Kubernetes. A namespace label injection vulnerability in Capsule v0.10.3 and earlier allows authenticated tenant users to inject arbitrary labels into system namespaces (kube-system, default, capsule-system), bypassing multi-tenant isolation and potentially accessing cross-tenant resources through TenantResource selectors. This vulnerability enables privilege escalation and violates the fundamental security boundaries that Capsule is designed to enforce. This vulnerability is fixed in 0.10.4.
Patch / fix
- go github.com/projectcapsule/capsule 0.10.4
- clastix capsule 0.10.4
- projectcapsule capsule 0.10.4
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 14 mo ago
Exploit prediction
0.49% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 9.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/projectcapsule/capsule | <0.10.4 |
0.10.4 |
Affected products
- projectcapsule capsule
Classification
- Weakness
-
- CWE-863 Incorrect Authorization
References
-
github.com
/projectcapsule/capsule/commit/e1f47feade6e1695b2204407607d07c3b3994f6e
web, patch
-
github.com
/projectcapsule/capsule/security/advisories/GHSA-fcpm-6mxq-m5vv
web, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2025-55205
advisory
-
github.com
/projectcapsule/capsule
package
-
pkg.go.dev
/vuln/GO-2025-3893
web
Sources
- CVE List CVE-2025-55205
- GitHub Advisory GHSA-fcpm-6mxq-m5vv
- NVD CVE-2025-55205
- OSV GO-2025-3893
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.