CVE-2026-56777

Full vulnerability record from the local CVENow database.

Description

n8n before 2.25.7 and 2.26.x before 2.26.2 contains an abstract syntax tree (AST) security validator bypass in the Python Code node. An authenticated user with permission to create or modify workflows containing a Python Code node can bypass the validator and access the task executor module namespace. The issue only affects self-hosted instances where the Python Task Runner is enabled; where N8N_BLOCK_RUNNER_ENV_ACCESS is configured to allow it, this can disclose environment variables accessible to the task runner process.

Severity

MEDIUM

CVSS score

5.3 (v4.0)

Vulnerability status

Analyzed

Source identifier

[email protected]

Published

2026-06-30 23:17:32.413000

Last modified

2026-10-29 19:17:23.337000

View original CVE JSON

{
  "id": "CVE-2026-56777",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-30T23:17:32.413",
  "lastModified": "2026-10-29T19:17:23.337",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "n8n before 2.25.7 and 2.26.x before 2.26.2 contains an abstract syntax tree (AST) security validator bypass in the Python Code node. An authenticated user with permission to create or modify workflows containing a Python Code node can bypass the validator and access the task executor module namespace. The issue only affects self-hosted instances where the Python Task Runner is enabled; where N8N_BLOCK_RUNNER_ENV_ACCESS is configured to allow it, this can disclose environment variables accessible to the task runner process."
    },
    {
      "lang": "es",
      "value": "n8n anterior a 2.25.7 y 2.26.x anterior a 2.26.2 contiene una omisión del validador de seguridad del árbol de sintaxis abstracta (AST) en el nodo de Código Python. Un usuario autenticado con permiso para crear o modificar flujos de trabajo que contengan un nodo de Código Python puede omitir el validador y acceder al espacio de nombres del módulo ejecutor de tareas. El problema solo afecta a instancias autoalojadas donde el Ejecutor de Tareas Python está habilitado; donde N8N_BLOCK_RUNNER_ENV_ACCESS está configurado para permitirlo, esto puede divulgar variables de entorno accesibles para el proceso del ejecutor de tareas."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "n8n",
          "product": "n8n",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/n8n",
          "versions": [
            {
              "version": "2.26.0",
              "lessThan": "2.26.2",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "2.26.2",
              "versionType": "semver",
              "status": "unaffected"
            }
          ]
        },
        {
          "vendor": "n8n",
          "product": "n8n",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/n8n",
          "versions": [
            {
              "version": "0",
              "lessThan": "2.25.7",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "2.25.7",
              "versionType": "semver",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "LOW",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N",
          "baseScore": 5.0,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.1,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-01T13:49:24.886291Z",
          "id": "CVE-2026-56777",
          "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-184"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*",
              "versionEndExcluding": "2.25.7",
              "matchCriteriaId": "BF3AA8D6-D35E-4D7B-B4E5-819275C0C91B"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*",
              "versionStartIncluding": "2.26.0",
              "versionEndExcluding": "2.26.2",
              "matchCriteriaId": "970A6AA3-03FF-4B9D-85C1-462C5C7F7171"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/n8n-io/n8n/security/advisories/GHSA-jwm3-qcfw-c5pp",
      "source": "[email protected]",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.vulncheck.com/advisories/n8n-ast-validator-bypass-in-python-code-node",
      "source": "[email protected]",
      "tags": [
        "Third Party Advisory"
      ]
    }
  ]
}