CVE-2026-56777 | n8n before 2.25.7 and 2.26.x before 2.26.2 contains an abstr… | CVSS 5.0 MEDIUM

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.

Metadata

CVE ID: CVE-2026-56777
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-23 01:22 UTC
Published: 2026-06-30 22:08 UTC
Last updated: 2026-07-01 13:49 UTC
Primary CWE: CWE-184
Incomplete List of Disallowed Inputs
Vendor / Product: n8n / n8n
Sources: cve.org · NVD

Severity & Metrics

5.0 MEDIUM CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: partial

Affected products (2)

Vendor	Product	Platform	Versions
n8n	n8n	—	0 < 2.26.2, 2.26.2
n8n	n8n	—	0 < 2.25.7, 2.25.7

Weakness (CWE)

CWE	Source	Description
CWE-184	cna	Incomplete List of Disallowed Inputs

CVSS scores (2)

Score	Severity	Version	Source	Vector
5.3	MEDIUM	4.0	cna	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
5.0	MEDIUM	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

References (2)

GitHub Security Advisory (GHSA-jwm3-qcfw-c5pp) https://github.com/n8n-io/n8n/security/advisories/GHSA-jwm3-qcfw-c5pp
VulnCheck Advisory: n8n - AST Validator Bypass in Python Code Node https://www.vulncheck.com/advisories/n8n-ast-validator-bypass-in-python-code-node