GHSA-35jj-42hp-8gmq: Npm/n8n vulnerability
Impact
The /chat WebSocket route resumed a paused execution from a resume token without checking that the node being resumed was a chat node. n8n hands that token to anonymous form submitters, so a party with no account could present it on the chat route and release an execution waiting at an approval gate, the control an author puts in front of an action considered too consequential to automate. The patch restricts resume over the chat route and Chat Hub to chat-capable node types.
Patches
The issue has been fixed in n8n versions 2.37.7 and 2.38.2. 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: - Restrict n8n instance access to fully trusted users only. - Avoid workflows that combine a Form Trigger with non-chat approval gates (Send-and-Wait, Telegram/Slack/Gmail HITL, or plain Wait nodes) on publicly accessible instances. - Audit recent executions of such workflows for unexpected completion without a corresponding approval callback.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.37.7 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.38.2 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.37.7 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.38.2 - Configuration
Restrict n8n instance access to fully trusted users only (as a short-term mitigation if upgrade is not immediately possible).
n8n instance Authentication/authorization for access to instance = fully trusted users only - Compensating control
Audit recent executions of workflows that may include approval callbacks, and look for unexpected completion without a corresponding approval callback; treat any such cases as suspicious.
- Compensating control
Avoid workflows that combine a Form Trigger with non-chat approval gates (Send-and-Wait, Telegram/Slack/Gmail HITL, or plain Wait nodes) on publicly accessible instances.
Event History
Frequently Asked Questions
Which deployments are most exposed to this issue?
Publicly accessible n8n instances are most exposed when workflows combine a Form Trigger with non-chat approval gates, such as Send-and-Wait, Telegram, Slack, Gmail HITL, or plain Wait nodes. Anonymous form submitters can receive the relevant resume token.
What does an attacker need to exploit the issue?
The attacker needs a resume token issued to an anonymous form submitter and must present it through the /chat WebSocket route. No n8n account is required.
What is the impact of successful exploitation?
An attacker can resume an execution paused at a non-chat approval gate, potentially causing a consequential action to proceed without the intended approval callback.
How can administrators reduce risk before upgrading?
Restrict the instance to fully trusted users and avoid publicly accessible workflows that combine Form Trigger nodes with non-chat approval gates. Audit recent executions of those workflows for unexpected completion without a corresponding approval callback; these measures are temporary and do not fully remediate the issue.
Which versions contain the fix?
Upgrade n8n to version 2.37.7, 2.38.2, or a later version.