CVE & CISA-KEV Catalog

CVE-2025-6515

MEDIUM
6.8
CVSS v3
NVD

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.

CWE-330

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged

Impact

ConfidentialityNone
IntegrityHigh
AvailabilityHigh

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

Exploit Intelligence

0.34%probability of exploitation in 30 days
26thpercentile

Low risk: more likely to be exploited than 26% of all known CVEs.

References

Other references1
Embed a live status badge for CVE-2025-6515
CVE-2025-6515 severity badge

Markdown

[![CVE-2025-6515](https://tridentstack.com/cve/badge/CVE-2025-6515.svg)](https://tridentstack.com/cve/CVE-2025-6515)

HTML

<a href="https://tridentstack.com/cve/CVE-2025-6515"><img src="https://tridentstack.com/cve/badge/CVE-2025-6515.svg" alt="CVE-2025-6515"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-10-21.