n8n-io n8n up to 1.123.21/2.9.2/2.10.0 Environment Variable NODES_EXCLUDE code injection

Summaryinfo

A vulnerability, which was classified as critical, was found in n8n-io n8n up to 1.123.21/2.9.2/2.10.0. This affects an unknown function of the component Environment Variable Handler. The manipulation of the argument NODES_EXCLUDE results in code injection. This vulnerability is identified as CVE-2026-27493. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in n8n-io n8n up to 1.123.21/2.9.2/2.10.0. Affected is some unknown functionality of the component Environment Variable Handler. The manipulation of the argument NODES_EXCLUDE with an unknown input leads to a code injection vulnerability. CWE is classifying the issue as CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

n8n is an open source workflow automation platform. Prior to versions 2.10.1, 2.9.3, and 1.123.22, a second-order expression injection vulnerability existed in n8n's Form nodes that could allow an unauthenticated attacker to inject and evaluate arbitrary n8n expressions by submitting crafted form data. When chained with an expression sandbox escape, this could escalate to remote code execution on the n8n host. The vulnerability requires a specific workflow configuration to be exploitable. First, a form node with a field interpolating a value provided by an unauthenticated user, e.g. a form submitted value. Second, the field value must begin with an `=` character, which caused n8n to treat it as an expression and triggered a double-evaluation of the field content. There is no practical reason for a workflow designer to prefix a field with `=` intentionally — the character is not rendered in the output, so the result would not match the designer's expectations. If added accidentally, it would be noticeable and very unlikely to persist. An unauthenticated attacker would need to either know about this specific circumstance on a target instance or discover a matching form by chance. Even when the preconditions are met, the expression injection alone is limited to data accessible within the n8n expression context. Escalation to remote code execution requires chaining with a separate sandbox escape vulnerability. The issue has been fixed in n8n versions 2.10.1, 2.9.3, and 1.123.22. Users should upgrade to one of these versions or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations. Review usage of form nodes manually for above mentioned preconditions, disable the Form node by adding `n8n-nodes-base.form` to the `NODES_EXCLUDE` environment variable, and/or disable the Form Trigger node by adding `n8n-nodes-base.formTrigger` to the `NODES_EXCLUDE` environment variable. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-27493 since 02/19/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.

Upgrading to version 1.123.22, 2.9.3 or 2.10.1 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 562d867483e871b0f1e31776252e23bd721df75b is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-0532). Once again VulDB remains the best source for vulnerability data.

Affected

• n8n n8n

Productinfo

Vendor

• n8n-io

Name

• n8n

Version

• 1.123.0
• 1.123.1
• 1.123.2
• 1.123.3
• 1.123.4
• 1.123.5
• 1.123.6
• 1.123.7
• 1.123.8
• 1.123.9
• 1.123.10
• 1.123.11
• 1.123.12
• 1.123.13
• 1.123.14
• 1.123.15
• 1.123.16
• 1.123.17
• 1.123.18
• 1.123.19
• 1.123.20
• 1.123.21
• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.9.0
• 2.9.1
• 2.9.2
• 2.10.0

License

• open-source

Website

• Product: https://github.com/n8n-io/n8n/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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