mcp-neo4j 0.3.0 SSE Service Command Injection
CVE-2025-56406 Published on September 10, 2025
An issue was discovered in mcp-neo4j 0.3.0 allowing attackers to obtain sensitive information or execute arbitrary commands via the SSE service. NOTE: the Supplier's position is that authentication is not mandatory for MCP servers, and the mcp-neo4j MCP server is only intended for use in a local environment where authentication realistically would not be needed. Also, the Supplier provides middleware to help isolate the MCP server from external access (if needed).
Vulnerability Analysis
CVE-2025-56406 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Weakness Types
What is an Authorization Vulnerability?
The software does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
CVE-2025-56406 has been classified to as an Authorization vulnerability or weakness.
What is a Command Injection Vulnerability?
The software constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
CVE-2025-56406 has been classified to as a Command Injection vulnerability or weakness.
What is an Information Disclosure Vulnerability?
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
CVE-2025-56406 has been classified to as an Information Disclosure vulnerability or weakness.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.