What’s Vulnerable › Vulnerabilities

CVE-2026-56777: n8n - AST Validator Bypass in Python Code Node

• Severity: medium (CVSS 5.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-30 · updated 2026-10-29
• Weakness: CWE-184

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.

Affected products

• n8n-io n8n: before 2.25.7; from 2.26.0 before 2.26.2 — fixed in 2.25.7, 2.26.2
• n8n-io n8n: from 2.26.0 before 2.26.2 — fixed in 2.26.2

How to fix

Upgrade to a fixed version: n8n-io n8n 2.25.7, 2.26.2; n8n-io n8n 2.26.2. Check the vendor advisory for mitigations.

References

• https://github.com/n8n-io/n8n/security/advisories/GHSA-jwm3-qcfw-c5pp
• https://www.vulncheck.com/advisories/n8n-ast-validator-bypass-in-python-code-node

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