« Volver al listado

CVE-2026-40933

Estado: AnalizadaCrítica (9.9)—

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.0, due to unsafe serialization of stdio commands in the MCP adapter, an authenticated attacker can add an MCP stdio server with an arbitrary command, achieving command execution.

Leer descripción completaMostrar menos

The vulnerability lies in a bug in the input sanitization from the “Custom MCP” configuration in http://localhost:3000/canvas - where any user can add a new MCP, when doing so - adding a new MCP using stdio, the user can add any command, even though your code have input sanitization checks such as validateCommandInjection and validateArgsForLocalFileAccess, and a list of predefined specific safe commands - these commands, for example "npx" can be combined with code execution arguments ("-c touch /tmp/pwn") that enable direct code execution on the underlying OS. This vulnerability is fixed in 3.1.0.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

AV:N/PR:L indica acceso remoto autenticado sin privilegios iniciales (T1210). CWE-78 + bypass de sanitización permite ejecución de comandos OS arbitrarios (T1059). UI:N y S:C con impacto crítico sugieren potencial escalada a root/admin (T1068).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Threat Intelligence ProgramPrivileged Account ManagementExecution PreventionDisable or Remove Feature or ProgramApplication Isolation and SandboxingExploit Protection

Tecnologías afectadas (1)

Flowiseai — Flowise

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-40933",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-40933",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-04-22T13:20:05.790341Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 9.9,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 6,
        "exploitabilityScore": 3.1
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "FlowiseAI",
          "product": "Flowise",
          "versions": [
            {
              "status": "affected",
              "version": "< 3.1.0"
            }
          ]
        },
        {
          "vendor": "FlowiseAI",
          "product": "flowise-components",
          "versions": [
            {
              "status": "affected",
              "version": "< 3.1.0"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-04-21T22:16:19.383",
  "references": [
    {
      "url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-c9gw-hvqq-f33r",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://www.ox.security/blog/mcp-supply-chain-advisory-rce-vulnerabilities-across-the-ai-ecosystem",
      "tags": [
        "Press/Media Coverage",
        "Third Party Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://www.ox.security/blog/the-mother-of-all-ai-supply-chains-critical-systemic-vulnerability-at-the-core-of-the-mcp",
      "tags": [
        "Press/Media Coverage",
        "Third Party Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-c9gw-hvqq-f33r",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-78"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.0, due to unsafe serialization of stdio commands in the MCP adapter, an authenticated attacker can add an MCP stdio server with an arbitrary command, achieving command execution. The vulnerability lies in a bug in the input sanitization from the “Custom MCP” configuration in http://localhost:3000/canvas - where any user can add a new MCP, when doing so - adding a new MCP using stdio, the user can add any command, even though your code have input sanitization checks such as validateCommandInjection and validateArgsForLocalFileAccess, and a list of predefined specific safe commands - these commands, for example \"npx\" can be combined with code execution arguments (\"-c touch /tmp/pwn\") that enable direct code execution on the underlying OS. This vulnerability is fixed in 3.1.0."
    }
  ],
  "lastModified": "2026-06-17T10:45:54.440",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "CB30DB8F-4F72-4FD3-90FB-8331F1CBB78E",
              "versionEndExcluding": "3.1.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security-advisories@github.com"
}