PYSEC-2026-1620
Neo4j Cypher MCP server is vulnerable to DNS rebinding
Details
### 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://neo4j.com/security/cve-2025-10193) https://www.cve.org/CVERecord?id=CVE-2025-10193
Credits We want to publicly recognize the contribution of Evan Harris from [mcpsec.dev](https://mcpsec.dev/) for reporting this issue and following the responsible disclosure [policy](https://neo4j.com/trust-center/responsible-disclosure/).
Are you affected?
Enter the version of the package you're using.
Affected packages
0.2.2 Fixed in: 0.4.0 pip install --upgrade 'mcp-neo4j-cypher>=0.4.0' References
- https://github.com/neo4j-contrib/mcp-neo4j/security/advisories/GHSA-vcqx-v2mg-7chx [WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2025-10193 [ADVISORY]
- https://github.com/neo4j-contrib/mcp-neo4j/pull/165 [WEB]
- https://github.com/neo4j-contrib/mcp-neo4j/commit/5b9fbdda6401668d7aa006daf7e644805c067c15 [WEB]
- https://github.com/neo4j-contrib/mcp-neo4j [PACKAGE]
- https://github.com/neo4j-contrib/mcp-neo4j/releases/tag/mcp-neo4j-cypher-v0.4.0 [WEB]
- https://neo4j.com/security/cve-2025-10193 [WEB]
- https://pypi.org/project/mcp-neo4j-cypher [PACKAGE]
- https://github.com/advisories/GHSA-vcqx-v2mg-7chx [ADVISORY]