FKIE_CVE-2025-6515

Vulnerability from fkie_nvd - Published: 2025-10-20 17:15 - Updated: 2026-10-08 22:10
Severity
6.8 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H
Summary
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.
References
reefs@jfrog.comhttps://research.jfrog.com/vulnerabilities/oatpp-mcp-prompt-hijacking-jfsa-2025-001494691/
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "oatpp-mcp",
          "vendor": "oatpp",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "cpe"
            }
          ]
        }
      ],
      "source": "reefs@jfrog.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    },
    {
      "lang": "es",
      "value": "El endpoint MCP SSE en oatpp-mcp devuelve un puntero de instancia como el ID de sesi\u00f3n, el cual no es \u00fanico ni criptogr\u00e1ficamente seguro. Esto permite a atacantes de red con acceso al servidor oatpp-mcp adivinar futuros ID de sesi\u00f3n y secuestrar sesiones MCP de clientes leg\u00edtimos, devolviendo respuestas maliciosas desde el servidor oatpp-mcp."
    }
  ],
  "id": "CVE-2025-6515",
  "lastModified": "2026-10-08T22:10:00.563",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 6.8,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 5.2,
        "source": "reefs@jfrog.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-6515",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-10-20T16:33:42.234883Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-10-20T17:15:39.197",
  "references": [
    {
      "source": "reefs@jfrog.com",
      "url": "https://research.jfrog.com/vulnerabilities/oatpp-mcp-prompt-hijacking-jfsa-2025-001494691/"
    }
  ],
  "sourceIdentifier": "reefs@jfrog.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-330"
        }
      ],
      "source": "reefs@jfrog.com",
      "type": "Secondary"
    }
  ]
}



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