CVE-2026-24176: NVIDIA KAI Scheduler Auth Bypass Flaw

CVE-2026-24176 Overview

NVIDIA KAI Scheduler contains an improper authorization vulnerability (CWE-863) that allows an attacker to exploit cross-namespace pod references. This authorization bypass flaw enables attackers with low-privilege access to reference pods across Kubernetes namespaces, potentially leading to data tampering within affected container orchestration environments.

Critical Impact

Successful exploitation of this vulnerability could allow attackers to tamper with data by leveraging improper cross-namespace pod authorization controls in NVIDIA KAI Scheduler deployments.

Affected Products

• NVIDIA KAI Scheduler (specific versions not disclosed)

Discovery Timeline

• 2026-04-21 - CVE-2026-24176 published to NVD
• 2026-04-22 - Last updated in NVD database

Technical Details for CVE-2026-24176

Vulnerability Analysis

This vulnerability stems from improper authorization handling (CWE-863) within the NVIDIA KAI Scheduler component. The flaw exists in how the scheduler processes pod references across Kubernetes namespaces. When an authenticated attacker with low-level privileges submits specially crafted requests, the scheduler fails to properly validate namespace boundaries for pod references. This allows cross-namespace access that should be restricted by Kubernetes' native security model.

The attack requires network access and low-privilege authentication but does not require user interaction. The primary impact is to data integrity, as successful exploitation could enable unauthorized modification of pod configurations or scheduling decisions across namespace boundaries.

Root Cause

The root cause is improper authorization checks when validating cross-namespace pod references within the KAI Scheduler. The scheduler does not adequately verify that requesting entities have proper authorization to reference pods in different namespaces, violating the principle of least privilege and namespace isolation that is fundamental to Kubernetes security architecture.

Attack Vector

The vulnerability is exploitable over the network by authenticated users with low-level privileges. An attacker would need to:

1. Gain authenticated access to a Kubernetes cluster running NVIDIA KAI Scheduler
2. Craft requests that reference pods in namespaces outside their authorized scope
3. Submit these cross-namespace pod references through the scheduler's API
4. Exploit the improper authorization to tamper with data or configurations in other namespaces

The attack does not require user interaction and operates within an unchanged scope, affecting only the integrity of the vulnerable component without impacting confidentiality or availability directly.

Detection Methods for CVE-2026-24176

Indicators of Compromise

• Unusual cross-namespace pod reference requests in KAI Scheduler audit logs
• Scheduling decisions or pod configurations modified by users without proper namespace permissions
• API requests to the scheduler that reference pods in multiple namespaces from a single authenticated session

Detection Strategies

• Enable and monitor Kubernetes audit logging for the KAI Scheduler component, specifically filtering for cross-namespace operations
• Implement namespace-aware RBAC monitoring to detect authorization bypass attempts
• Deploy admission controllers to validate namespace boundaries on scheduler requests
• Configure alerts for pod reference patterns that span multiple namespaces from low-privilege service accounts

Monitoring Recommendations

• Review KAI Scheduler logs for anomalous cross-namespace activity patterns
• Monitor Kubernetes API server audit logs for unauthorized namespace access attempts
• Implement network segmentation monitoring between namespace boundaries
• Track changes to pod configurations that originate from unexpected namespaces

How to Mitigate CVE-2026-24176

Immediate Actions Required

• Review NVIDIA's security advisory for patch availability at the NVIDIA Customer Support Response
• Audit current KAI Scheduler configurations for cross-namespace pod reference settings
• Implement strict RBAC policies limiting cross-namespace access until patches are applied
• Enable comprehensive audit logging on the KAI Scheduler component

Patch Information

NVIDIA has acknowledged this vulnerability through their customer support portal. Organizations should consult the NVIDIA Customer Support Response for specific patch versions and update instructions. Apply vendor-provided updates as soon as they become available for your environment.

Workarounds

• Restrict KAI Scheduler API access to only trusted, high-privilege service accounts
• Implement Kubernetes NetworkPolicies to limit cross-namespace communication
• Deploy OPA Gatekeeper or Kyverno policies to enforce namespace isolation for pod references
• Consider temporarily disabling cross-namespace features in the scheduler if operationally feasible

# Example: Restrict namespace access with RBAC
kubectl create rolebinding kai-scheduler-restricted \
  --role=kai-scheduler-role \
  --serviceaccount=your-namespace:kai-scheduler-sa \
  --namespace=your-namespace