CVE-2026-54446

Overview

The NetLicensing MCP Server prior to version 0.1.6 suffers from an authentication bypass vulnerability in its HTTP transport endpoint at /mcp. Requests lacking authentication credentials fail to be rejected by the ApiKeyMiddleware, causing the application to fall back to the operator's stored API key. This allows unauthenticated remote attackers to execute unauthorized licensing lifecycle management actions.

Description

NetLicensing MCP Server is a natural-language interface that enables agentic applications to manage the software-licensing lifecycle in Labs64 NetLicensing. Prior to 0.1.6, network-reachable HTTP transport requests to /mcp that omit x-netlicensing-api-key, Authorization: Bearer, and the apikey query parameter pass through ApiKeyMiddleware in src/netlicensing_mcp/server.py without authentication. The downstream api_key_ctx in src/netlicensing_mcp/client.py then falls back to the operator's NETLICENSING_API_KEY and authenticates upstream NetLicensing REST API calls under the operator account. An unauthenticated attacker can invoke MCP tools to enumerate products, licenses, licensees, and transactions, create or modify licensing objects, perform validations, and execute destructive delete operations. The issue affects HTTP deployments configured with a server-side key and does not require user interaction. This issue is fixed in version 0.1.6.

Impact

This vulnerability impacts confidentiality, integrity, and availability by allowing unauthenticated remote threat actors to enumerate products and licenses, modify licensing data, perform validations, and execute destructive delete operations. The affected parties are organizations deploying the vulnerable MCP server with server-side API keys configured. The fallout includes potential exposure of sensitive license data and unauthorized disruption of software licensing operations.

Remediation

Upgrade the NetLicensing MCP Server to version 0.1.6 or later immediately where the authentication middleware issue is resolved. Ensure that network-level access controls restrict external reachability to the /mcp HTTP transport endpoint if public exposure is not strictly required. Review server and upstream API logs for anomalous unauthenticated requests or unexpected licensing modifications.

Risk context

This vulnerability is rated as high severity with a CVSS v3 score of 8.1, reflecting the severe impact of unauthenticated destructive actions and data exposure. Immediate patching is recommended for all deployments exposed via HTTP transport.

Affected products

• Labs64 NetLicensing MCP Server < 0.1.6