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.
Exploitability
AV:NAC:HPR:NUI:RScope
S:UImpact
C:NI:HA:H6.8/CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:HCryptography