CVE-2026-14450: MaaS API Auth Bypass Vulnerability

CVE-2026-14450 Overview

CVE-2026-14450 is an authentication bypass vulnerability in the Models-as-a-Service (MaaS) API. The API trusts the X-MaaS-Username and X-MaaS-Group HTTP headers verbatim without first-party authentication. Any pod within the cluster can forge these headers to bypass the Kuadrant AuthPolicy gateway and impersonate arbitrary users or groups.

Successful exploitation lets an attacker mint Kubernetes ServiceAccount tokens in other tenants' namespaces, revoke API keys, and exfiltrate sensitive model access configuration. The flaw is tracked as CWE-290: Authentication Bypass by Spoofing.

Critical Impact
Attackers with in-cluster network access can impersonate any tenant, mint cross-namespace ServiceAccount tokens, and exfiltrate model access secrets.

Affected Products

Red Hat MaaS API (see RHSA-2026:53262)
Deployments relying on Kuadrant AuthPolicy gateway for MaaS authentication
Multi-tenant Kubernetes environments running the affected MaaS component

Discovery Timeline

2026-08-10 - CVE-2026-14450 published to NVD
2026-08-11 - Last updated in NVD database

Technical Details for CVE-2026-14450

Vulnerability Analysis

The MaaS API delegates identity assertions to upstream request headers instead of validating them against a trusted authentication source. The application reads X-MaaS-Username and X-MaaS-Group from incoming HTTP requests and treats those values as authoritative identity claims.

The Kuadrant AuthPolicy gateway is intended to enforce authentication before requests reach the API. However, any workload with network reachability to the API service inside the cluster can bypass the gateway entirely and send requests directly to the backend with attacker-controlled headers.

Once the API accepts the forged identity, downstream authorization logic grants tenant-scoped privileges based on those spoofed values. This enables privilege escalation across tenant boundaries within the same Kubernetes cluster.

Root Cause

The root cause is missing first-party authentication in the MaaS API itself. The service depends on a network-layer gateway to attach identity headers but performs no cryptographic verification, signed token validation, or mutual TLS check to confirm that the headers originated from the gateway. This design assumes an intact perimeter that does not hold in a shared-cluster threat model.

Attack Vector

An attacker with the ability to run a pod in the cluster crafts an HTTP request directly to the MaaS API service, setting X-MaaS-Username and X-MaaS-Group to the target tenant identity. The request bypasses the Kuadrant gateway because pod-to-service traffic is not forced through the ingress path.

The attacker then invokes privileged endpoints to mint Kubernetes ServiceAccount tokens scoped to other tenants' namespaces, revoke API keys belonging to other tenants, or read stored model access configuration. No user interaction is required, and the attacker needs only low-level privileges to schedule a pod.

No verified exploit code has been published. See the Red Hat CVE-2026-14450 advisory for technical details.

Detection Methods for CVE-2026-14450

Indicators of Compromise

Requests to the MaaS API containing X-MaaS-Username or X-MaaS-Group headers that did not traverse the Kuadrant AuthPolicy gateway
Unexpected TokenRequest API calls creating ServiceAccount tokens in namespaces the source workload does not own
API key revocation events initiated from unusual source pods or service accounts
Reads of model access configuration secrets by workloads outside the owning tenant namespace

Detection Strategies

Correlate MaaS API access logs with Kuadrant gateway logs to identify requests that reached the backend without a matching gateway entry
Alert on any in-cluster source IP invoking MaaS API endpoints while carrying identity headers, since legitimate traffic should originate from the gateway only
Monitor Kubernetes audit logs for serviceaccounts/token subresource requests that cross tenant namespace boundaries

Monitoring Recommendations

Enable Kubernetes API server audit logging at RequestResponse level for secrets, serviceaccounts, and tokenreviews resources
Ingest MaaS API application logs and Kuadrant access logs into a central SIEM for cross-correlation
Track anomalous spikes in API key revocation and token mint operations grouped by tenant

How to Mitigate CVE-2026-14450

Immediate Actions Required

Apply the fixed MaaS API build referenced in RHSA-2026:53262 as soon as it is available in your channel
Restrict network access to the MaaS API service using a NetworkPolicy that only permits ingress from the Kuadrant gateway pods
Rotate any API keys and ServiceAccount tokens that may have been exposed while the vulnerability was reachable
Audit recent TokenRequest and secret-access events across tenant namespaces for cross-tenant activity

Patch Information

Red Hat has issued security advisory RHSA-2026:53262 addressing this vulnerability. Additional context is available in the Red Hat CVE-2026-14450 details and Red Hat Bug Report #2496373. Upgrade to the fixed release and validate that the API rejects requests lacking a verifiable gateway-issued identity assertion.

Workarounds

Enforce mutual TLS between the Kuadrant gateway and the MaaS API so the backend validates the gateway certificate before accepting identity headers
Deploy a Kubernetes NetworkPolicy that blocks all pod-to-service traffic to the MaaS API except from the gateway namespace
Strip X-MaaS-Username and X-MaaS-Group at the gateway ingress and re-inject them only after successful authentication
Require signed identity tokens (for example, a JWT issued by the gateway) that the MaaS API validates before honoring any tenant claim

bash

# Example NetworkPolicy restricting MaaS API ingress to the Kuadrant gateway only
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: maas-api-gateway-only
  namespace: maas-system
spec:
  podSelector:
    matchLabels:
      app: maas-api
  policyTypes:
    - Ingress
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              kuadrant.io/gateway: "true"
          podSelector:
            matchLabels:
              app: kuadrant-gateway
      ports:
        - protocol: TCP
          port: 8443