CVE-2025-6515 — MEDIUM (6.8)

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.

CVSS Score

6.8

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

HIGH

Related Weaknesses (CWE)

CWE-330

References

https://research.jfrog.com/vulnerabilities/oatpp-mcp-prompt-hijacking-jfsa-2025-

FAQ

What is CVE-2025-6515?

CVE-2025-6515 is a vulnerability with a CVSS score of 6.8 (MEDIUM). 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 ...

How severe is CVE-2025-6515?

CVE-2025-6515 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2025-6515?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.