Holes in EndpointSlice Validation Enable Host Network Hijack
Priority LOW 19CWE-441Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.
Why it matters now
EPSS 0.01952 80th percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Kubernetes | Kubernetes | all versions | — | No fix listed | CNA |
| — | k8s.io/kubernetes (Go) | up to 1.22.2 | — | No fix listed | GHSA-vw47-mr44-3jf9 |
- Kubernetes VendorKubernetes Affected all versions Fixed in — No fix listed CNA
- k8s.io/kubernetes (Go) Vendor— Affected up to 1.22.2 Fixed in — No fix listed GHSA-vw47-mr44-3jf9
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:kubernetes:kubernetes:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Kubernetes |
- cpe:2.3:a:kubernetes:kubernetes:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Kubernetes
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenShift Container Platform 3.11 | Affected | No fix planned: Out of support scope |
Not affected: 1 product
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2021-25740
- 2026-10-03 Alias added: GHSA-vw47-mr44-3jf9
References
Advisory 4
More Kubernetes vulnerabilities
- TI-2018-16130 Improper privilege management in Kubernetes CVSS 3.0CRITICAL 9.8
- TI-2019-08418 Kubernetes kubelet exposes /debug/pprof info on healthz port CVSS 3.1HIGH 8.2
- TI-2023-05086 Kubernetes - Windows nodes - Insufficient input sanitization in in-tree storage plugin leads to privilege escalation CVSS 3.1HIGH 8.8
- TI-2023-03433 Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation CVSS 3.1HIGH 8.8
- TI-2023-02285 Bypass of seccomp profile enforcement CVSS 3.1MEDIUM 5.5
- TI-2017-14755 Link following in Kubernetes CVSS 3.0CRITICAL 9.6
Sources
- CVE-2021-25740 · CVE Program
- CVE-2021-25740 · NVD
- FIRST EPSS
- GHSA-vw47-mr44-3jf9 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-25740 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences