Security Advisory
CVE-2025-6515
6.8
MEDIUM
Vulnerability Description
The MCP SSE endpoint in oatpp-mcp returns an instance pointer as the session ID, which is not unique nor cryptographically secure. This allows network attackers with access to the oatpp-mcp server to guess future session IDs and hijack legitimate client MCP sessions, returning malicious responses from the oatpp-mcp server.
Published Date
October 20, 2025
Official Source
NIST NVD Advisory