CVE-2026-14537: Authorization Bypass in MCP Toolbox Legacy HTTP Endpoints
Incorrect Authorization in the direct HTTP API tool invocation endpoint in Google mcp-toolbox versions v1.3.0 and v1.4.0 allows an unauthenticated attacker to invoke tools protected by the scopeRequired feature via sending tool invocation requests through legacy HTTP endpoints when the --enable-api flag is active.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Google mcp-toolboxto a version that resolves this vulnerability.Fixed in v1.3.0 - Upgrade
Upgrade
Google mcp-toolboxto a version that resolves this vulnerability.Fixed in v1.4.0 - Configuration
Disable the legacy HTTP API invocation by turning off the --enable-api flag to prevent requests from reaching the direct HTTP API tool invocation endpoint.
Google mcp-toolbox --enable-api = disabled
Event History
Frequently Asked Questions
What is the severity of CVE-2026-14537?
The severity of CVE-2026-14537 is rated at 80, indicating a critical risk to affected systems.
What systems are affected by CVE-2026-14537?
CVE-2026-14537 affects Google mcp-toolbox versions v1.3.0 and v1.4.0.
How do I fix CVE-2026-14537?
To fix CVE-2026-14537, upgrade Google mcp-toolbox to a version that does not include the vulnerability.
What type of vulnerability is CVE-2026-14537?
CVE-2026-14537 is classified as an authorization bypass vulnerability.
How can CVE-2026-14537 be exploited?
An unauthenticated attacker can exploit CVE-2026-14537 by invoking tools protected by the scopeRequired feature through legacy HTTP endpoints.