Neo4j Cypher MCP server is vulnerable to DNS rebinding

Impact

DNS rebinding vulnerability in Neo4j Cypher MCP server allows malicious websites to bypass Same-Origin Policy protections and execute unauthorised tool invocations against locally running Neo4j MCP instances. The attack relies on the user being enticed to visit a malicious website and spend sufficient time there for DNS rebinding to succeed.

Patches

CORS Middleware added to Cypher MCP server v0.4.0 that blocks all web-based access by default.

Workarounds

If you cannot upgrade to v0.4.0 and above, use stdio mode.

References

Vendor Advisory https://www.cve.org/CVERecord?id=CVE-2025-10193

Credits We want to publicly recognize the contribution of Evan Harris from mcpsec.dev for reporting this issue and following the responsible disclosure policy.