CVE-2026-40933

{
  "id": "CVE-2026-40933",
  "sourceIdentifier": "[email protected]",
  "published": "2026-04-21T22:16:19.383",
  "lastModified": "2026-10-26T22:10:00.163",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "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."
    },
    {
      "lang": "es",
      "value": "Flowise es una interfaz de usuario de arrastrar y soltar para construir un flujo de modelo de lenguaje grande personalizado. Antes de la versión 3.1.0, debido a la serialización insegura de comandos stdio en el adaptador MCP, un atacante autenticado puede añadir un servidor stdio MCP con un comando arbitrario, logrando la ejecución de comandos. La vulnerabilidad reside en un error en la sanitización de entrada de la configuración ’Custom MCP’ en http://localhost:3000/canvas - donde cualquier usuario puede añadir un nuevo MCP, al hacerlo - añadiendo un nuevo MCP usando stdio, el usuario puede añadir cualquier comando, a pesar de que su código tiene comprobaciones de sanitización de entrada como validateCommandInjection y validateArgsForLocalFileAccess, y una lista de comandos seguros específicos predefinidos - estos comandos, por ejemplo ’npx’ pueden combinarse con argumentos de ejecución de código (’-c touch /tmp/pwn’) que permiten la ejecución directa de código en el sistema operativo subyacente. Esta vulnerabilidad está corregida en la versión 3.1.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "FlowiseAI",
          "product": "Flowise",
          "versions": [
            {
              "version": "< 3.1.0",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "FlowiseAI",
          "product": "flowise-components",
          "versions": [
            {
              "version": "< 3.1.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
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        "source": "[email protected]",
        "type": "Secondary",
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          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "baseScore": 9.9,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.1,
        "impactScore": 6.0
      }
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          "timestamp": "2026-04-22T13:20:05.790341Z",
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            },
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          "role": "CISA Coordinator",
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  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-78"
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  "references": [
    {
      "url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-c9gw-hvqq-f33r",
      "source": "[email protected]",
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      "source": "[email protected]",
      "tags": [
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      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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}