CVE-2026-44661

{
  "id": "CVE-2026-44661",
  "sourceIdentifier": "[email protected]",
  "published": "2026-05-14T21:16:47.100",
  "lastModified": "2026-10-26T14:10:00.130",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "python-utcp is the python implementation of UTCP. Prior to 1.1.3, the utcp-http plugin is vulnerable to a blind Server-Side Request Forgery (SSRF) caused by a trust-boundary inconsistency between manual discovery and tool invocation. register_manual() validates the discovery URL against an HTTPS / loopback allowlist, but call_tool() and call_tool_streaming() reuse the resolved tool_call_template.url directly without revalidating, and the OpenAPI converter blindly trusts whatever servers[0].url an attacker-hosted spec declares. An attacker who hosts a malicious OpenAPI spec on a legitimate HTTPS endpoint can declare e.g. servers: [{ url: \"http://127.0.0.1:9090\" }] or servers: [{ url: \"http://169.254.169.254\" }]; the OpenAPI converter then produces tools whose URL points at internal services on the agent host. All three HTTP-class protocols (utcp_http.http, utcp_http.streamable_http, utcp_http.sse) shared the same gap. This vulnerability is fixed in 1.1.3."
    },
    {
      "lang": "es",
      "value": "python-utcp es la implementación en python de UTCP. Antes de la versión 1.1.3, el plugin utcp-http es vulnerable a una falsificación de petición del lado del servidor (SSRF) ciega causada por una inconsistencia en el límite de confianza entre el descubrimiento manual y la invocación de herramientas. register_manual() valida la URL de descubrimiento contra una lista de permitidos de HTTPS / loopback, pero call_tool() y call_tool_streaming() reutilizan la URL tool_call_template.url resuelta directamente sin revalidar, y el conversor OpenAPI confía ciegamente en cualquier servers[0].url que declare una especificación alojada por un atacante. Un atacante que aloja una especificación OpenAPI maliciosa en un endpoint HTTPS legítimo puede declarar, por ejemplo, servers: [{ url: ’http://127.0.0.1:9090’ }] o servers: [{ url: ’http://169.254.169.254’ }]; el conversor OpenAPI produce entonces herramientas cuya URL apunta a servicios internos en el host del agente. Los tres protocolos de clase HTTP (utcp_http.http, utcp_http.streamable_http, utcp_http.sse) compartían la misma brecha. Esta vulnerabilidad está corregida en la versión 1.1.3."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "universal-tool-calling-protocol",
          "product": "python-utcp",
          "versions": [
            {
              "version": "< 1.1.2",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "CHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 2.7
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-15T11:24:39.658643Z",
          "id": "CVE-2026-44661",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/universal-tool-calling-protocol/python-utcp/security/advisories/GHSA-39j6-4867-gg4w",
      "source": "[email protected]"
    }
  ]
}