CVE-2026-56777
n8n - AST Validator Bypass in Python Code Node
- State
- Published
- Severity
- 5.3 Medium
- Published
- Jun 30, 2026
- Updated
- Oct 29, 2026
- Reserved
- Jun 23, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | 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 | VulnCheck |
| 3.1 | 5.0 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N | VulnCheck |
Weaknesses
- CWE-184 Incomplete List of Disallowed Inputs
Affected Products
| Product | Versions |
|---|---|
n8nn8n |
|
n8nn8n |
|
References
- GitHub Security Advisory (GHSA-jwm3-qcfw-c5pp)vendor-advisory
- VulnCheck Advisory: n8n - AST Validator Bypass in Python Code Nodethird-party-advisory
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