What’s Vulnerable › Vulnerabilities
CVE-2025-6515: Reuse of session IDs in oatpp-mcp leads to session hijacking and prompt hijacking by remote attackers
- Severity: medium (CVSS 6.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-10-20 · updated 2026-10-08
- Weakness: CWE-330
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.
Affected products
- oatpp-mcp: 0
References
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