n8n Vulnerable to Hijacking of Unauthenticated Chat Execution
Medium5.4CVE-2026-42228 · Published Apr 29, 2026 · updated May 8, 2026
## Impact The `/chat` WebSocket endpoint used by the Chat Trigger node's Hosted Chat feature did not verify that an incoming connection was authorized to interact with the target execution. An unauthenticated remote attacker who could identify a valid execution ID for a workflow in a waiting state could attach to that execution, receive the pending prompt intended for the legitimate user, and submit arbitrary input to resume or influence downstream workflow behavior. Exploitation requires the following conditions: - The instance exposes a public Hosted Chat workflow with authentication set to `None`. - A target execution is in a waiting state at the time of the attack. - The attacker can obtain or discover the execution ID of that waiting execution. ## Patches The issue has been fixed in n8n versions 1.123.32, 2.17.4, and 2.18.1. Users should upgrade to one of these versions or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Enable authentication on all Chat Trigger nodes by setting the Authentication field to `n8n User Auth` rather than `None`. These workarounds...
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| n8n npm | < 1.123.32 | 1.123.32 |
| >= 2.18.0, < 2.18.1 | 2.18.1 | |
| >= 2.0.0, < 2.17.4 | 2.17.4 |
Details and references
## Impact The `/chat` WebSocket endpoint used by the Chat Trigger node's Hosted Chat feature did not verify that an incoming connection was authorized to interact with the target execution. An unauthenticated remote attacker who could identify a valid execution ID for a workflow in a waiting state could attach to that execution, receive the pending prompt intended for the legitimate user, and submit arbitrary input to resume or influence downstream workflow behavior. Exploitation requires the following conditions: - The instance exposes a public Hosted Chat workflow with authentication set to `None`. - A target execution is in a waiting state at the time of the attack. - The attacker can obtain or discover the execution ID of that waiting execution. ## Patches The issue has been fixed in n8n versions 1.123.32, 2.17.4, and 2.18.1. Users should upgrade to one of these versions or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Enable authentication on all Chat Trigger nodes by setting the Authentication field to `n8n User Auth` rather than `None`. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures. --- n8n has adopted CVSS 4.0 as primary score for all security advisories. CVSS 3.1 vector strings are provided for backwards compatibility. CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
- CVSS 3.1
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-862
- Also known as
- CVE-2026-42228
More n8n advisories
All n8n| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Apr 29 | n8n has XML Node Prototype Pollution that to RCE Critical9.9Apr 29 | Critical9.9 | 1.123.32+2 more |
| Apr 29 | n8n has Prototype Pollution in XML Webhook Body Parser that Leads to RCECritical10.0Apr 29 | Critical10.0 | 1.123.32+2 more |
| Apr 29 | n8n Vulnerable to XSS via MCP OAuth clientHigh8.2Apr 29 | High8.2 | 1.123.32+2 more |
| Apr 29 | n8n's Credential Authorization Bypass in dynamic-node-parameters Allows Foreign API Key ReplayHigh8.5Apr 29 | High8.5 | 1.123.33+1 more |
| Apr 29 | n8n has a Python Task Runner Sandbox Escape VulnerabilityHigh7.5Apr 29 | High7.5 | 1.123.32+2 more |
| Apr 29 | n8n has Public API Variables IDOR that Allows Cross-Project Secret DisclosureMedium7.7Apr 29 | Medium7.7 | 1.123.32+2 more |