Vulnerability · Published Jun 30, 2026 · Assigned by VulnCheck

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

Medium 5.0

In plain English

A medium-severity security flaw in n8n from n8n. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.0Medium

Exploit odds (30 days)0.3%top 74.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	n8n	2.26.2	GHSA-jwm3-qcfw-c5pp
npm	n8n	2.25.7	GHSA-jwm3-qcfw-c5pp

Affected products (as reported)

Vendor	Product	Versions
n8n	n8n	2.26.0 – before 2.26.2
n8n	n8n	0 – before 2.25.7

Weakness: CWE-184 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

References

GitHub Security Advisory (GHSA-jwm3-qcfw-c5pp) vendor-advisory
VulnCheck Advisory: n8n - AST Validator Bypass in Python Code Node third-party-advisory