CVE-2025-6515

MEDIUM EPSS 26.3%

Published Oct 20, 20258mo ago · Modified Jun 17, 20262w ago

6.8 CVSS 3.1

Medium

Published Oct 20, 2025 8mo ago

Last Modified Jun 17, 2026 2w ago

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 Details

Base Score

6.8

Exploitability

1.6

Impact

5.2

Vector string

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

Threat Intelligence

EPSS Exploit Probability

26.3% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-330

References 1

research.jfrog.com https://research.jfrog.com/vulnerabilities/oatpp-mcp-prompt-hijacking-jfsa-2025-001494691/

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.