How broadly exploitable is this vulnerability in real deployments?

Exploitability is constrained by workflow design: only instances using Form/Form Trigger nodes that interpolate unauthenticated user input into expression-enabled fields and later re-evaluate that data are affected. Many workflows will not meet these conditions, and an attacker must either know or discover a susceptible form.

Does an attacker need authenticated access to exploit this issue?

Not necessarily. If a workflow exposes a public form, an unauthenticated attacker can submit crafted payloads to that endpoint and potentially trigger expression injection under the specific configuration conditions.

What is the safest general fix pattern from a design perspective?

The safest pattern is to ensure user-controlled values are never automatically treated as expressions. Expressions should only come from trusted, designer-controlled sources, and any value originating from end users must remain inert data even if it resembles expression syntax (such as starting with `=`).

Severity:

CRITICAL RISK

(9.0)

Second-Order Expression Injection (CWE-95) in n8n Form Nodes

CVE-2026-27493

Published:

Feb 25, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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CWE-78

CRITICAL RISK

CRITICAL

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Remote Code Execution

March 7, 2026

CWE-89

CRITICAL RISK

CRITICAL

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SQL Injection via PostgreSQL Array/Row Expressions (CWE-89) in WeKnora Query Engine

Remote Code Execution via SQL Injection on the Database Server

March 7, 2026

Vulnerability Type

Category:

Expression Injection / Code Injection

CWE:

CWE-94;CWE-95

Impact:

Arbitrary Expression Evaluation with Potential Remote Code Execution

Severity:

CRITICAL RISK

(9.0)

CVSS Version:

3.1

Vulnerability Type

Category:

Expression Injection / Code Injection

CWE:

CWE-94;CWE-95

Impact:

Arbitrary Expression Evaluation with Potential Remote Code Execution

Severity:

CRITICAL RISK

(9.0)

CVSS Version:

3.1

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Ask AI for summary of CodeAnt

Second-Order Expression Injection (CWE-95) in n8n Form Nodes

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

CRITICAL RISK

CRITICAL

(9.9)

Command Injection in MCP Stdio Configuration Validation (CWE-78) in WeKnora

CRITICAL RISK

CRITICAL

(9.9)

SQL Injection via PostgreSQL Array/Row Expressions (CWE-89) in WeKnora Query Engine

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

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