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N8nApplication

CVE-2026-56777

MEDIUM · 5.0 CVSS v3.1 Published 2026-06-30
Fix available
A fix is available. Upgrade to 2.25.7 / 2.26.2 or later.
See remediation →
56/100
Remediation priority · Elevated
Remotely reachable Zero-click 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

n8n before 2.25.7 and 2.26.2 contains an AST security validator bypass in the Python Code node. Authenticated users with workflow create/modify permissions can bypass the validator to access the task executor module namespace. When the Python Task Runner is enabled and N8N_BLOCK_RUNNER_ENV_ACCESS is configured to allow it, this can expose environment variables accessible to the task runner process.

MitigationUpgrade n8n to version 2.25.7 or 2.26.2 or later. Ensure N8N_BLOCK_RUNNER_ENV_ACCESS is properly configured to restrict environment variable access, and review user permissions for workflow creation/modification in self-hosted instances.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
N8nApplication
Affected:< 2.25.7>= 2.26.0, < 2.26.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check n8n version
    Run 'n8n --version' or check the version displayed in the UI footer. Alternatively, inspect the package.json file in the n8n installation directory.
    Affected if Version is before 2.25.7 or between 2.26.0 and 2.26.1 (inclusive)
  2. Verify Python Task Runner is enabled
    Check the n8n configuration file (config.yaml or environment variables) for settings related to Python Task Runner, or inspect the task runner settings in the n8n UI under Settings > Processors.
    Affected if Python Task Runner is enabled and active
  3. Inspect N8N_BLOCK_RUNNER_ENV_ACCESS setting
    Check the environment variable N8N_BLOCK_RUNNER_ENV_ACCESS or the corresponding config.yaml setting. Run 'echo $N8N_BLOCK_RUNNER_ENV_ACCESS' or review the configuration file.
    Affected if N8N_BLOCK_RUNNER_ENV_ACCESS is not set to a restrictive value (such as 'true' or '1') or is missing entirely, allowing environment variable access
  4. Confirm user permissions
    Review which users or roles have workflow create or modify permissions in the n8n user management settings or in your authentication provider if using SSO.
    Affected if Any authenticated user has workflow create or modify permissions (this is the prerequisite for exploitation)

You are affected if your n8n version is vulnerable AND the Python Task Runner is enabled AND N8N_BLOCK_RUNNER_ENV_ACCESS is not configured to block environment variable access, AND untrusted users have workflow create/modify permissions.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.25.7 / 2.26.2 or later
Fixed in 2.25.72.26.2
Interim mitigation

Upgrade n8n to version 2.25.7 or 2.26.2 or later. Ensure N8N_BLOCK_RUNNER_ENV_ACCESS is properly configured to restrict environment variable access, and review user permissions for workflow creation/modification in self-hosted instances.

Recommended fix High confidence

n8n version 2.25.7 (2.25.x branch) or version 2.26.2 (2.26.x branch)

  1. Upgrade n8n to version 2.25.7 or later if using the 2.25.x branch
  2. OR upgrade n8n to version 2.26.2 or later if using the 2.26.x branch
  3. After upgrading, verify that the Python Code node AST validator is functioning correctly
  4. If you previously configured N8N_BLOCK_RUNNER_ENV_ACCESS to allow environment variable access, review whether this configuration is still needed post-patch
Caveat If you rely on N8N_BLOCK_RUNNER_ENV_ACCESS for workflow functionality, verify that the fix does not break existing workflows that depend on environment variable access via the Python Code node

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in N8n Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-56777 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data