CVE-2025-6515
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:Oct 20, 2025
Last Modified:Apr 15, 2026
EPS:Oct 20, 2025
EPSS Score:0.00042
CVSS Score:6.8
Affected Products
Vendor
Product
Action
Vendor
Oatpp
Product
Mcp
Oatpp
Mcp
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
