CVE-2025-6515EPSS p32.4%

CVE-2025-6515CVE-2025-6515

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.

Scoring

CVSS 6.8 ()
VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H
EPSS0.40% probability of exploitation · percentile 32.4% · 2026-10-10T12:00:23Z
Last modified2026-10-08
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.