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.
CVE-2026-56777
CVSS base score
5.0 (v3.1)
Severity
MEDIUM
Attack vector
Network
Weakness
CWE-184
Last modified
October 29, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
Affected products
n8n n8n
References
- github.com Mitigation, Vendor Advisory
- www.vulncheck.com Third Party Advisory