CVE-2026-56777
n8n - AST Validator Bypass in Python Code Node
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.
INFO
Published Date :
June 30, 2026, 11:17 p.m.
Last Modified :
July 2, 2026, 7:39 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update n8n to version 2.26.2 or later.
- Ensure Python Task Runner is disabled if not needed.
- Review and restrict access to the task executor module.
- Configure N8N_BLOCK_RUNNER_ENV_ACCESS appropriately.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-56777.
| URL | Resource |
|---|---|
| https://github.com/n8n-io/n8n/security/advisories/GHSA-jwm3-qcfw-c5pp | Mitigation Vendor Advisory |
| https://www.vulncheck.com/advisories/n8n-ast-validator-bypass-in-python-code-node | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56777 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-56777
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-56777 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56777 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 02, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:* versions from (including) 2.26.0 up to (excluding) 2.26.2 *cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:* versions up to (excluding) 2.25.7 Added Reference Type VulnCheck: https://github.com/n8n-io/n8n/security/advisories/GHSA-jwm3-qcfw-c5pp Types: Mitigation, Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/n8n-ast-validator-bypass-in-python-code-node Types: Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 01, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-56777', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-01T13:49:24.886291Z'} -
New CVE Received by [email protected]
Jun. 30, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'n8n', 'product': 'n8n', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '2.26.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '2.26.2', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/n8n', 'defaultStatus': 'unaffected'}, {'vendor': 'n8n', 'product': 'n8n', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '2.25.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '2.25.7', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/n8n', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N Added CWE CWE-184 Added Reference https://github.com/n8n-io/n8n/security/advisories/GHSA-jwm3-qcfw-c5pp Added Reference https://www.vulncheck.com/advisories/n8n-ast-validator-bypass-in-python-code-node