CVE-2026-103260: n8n before 2.39.6 and 2.40.x before 2.40.1 Approval Bypass via Send and Wait Node
n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain an approval bypass vulnerability in the Send and Wait node's Approve Within Chat mode. Attackers can submit resume requests without verification of the requester's identity or approval permissions, allowing unauthenticated users to advance waiting executions and trigger guarded actions.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.39.6 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.40.1
Event History
Frequently Asked Questions
Which workflows are exposed to this issue?
Workflows that use the Send and Wait node in Approve Within Chat mode are exposed. The vulnerability affects n8n versions before 2.39.6, as well as version 2.40.0 before 2.40.1.
Does an attacker need an n8n account or approval privileges?
No. An unauthenticated attacker can submit resume requests because the affected mode does not verify the requester's identity or approval permissions.
What is the practical impact of a successful exploit?
An attacker can advance a waiting workflow execution and cause actions intended to be guarded by an approval step to run. The available information identifies integrity impact, not confidentiality or availability impact.
What should be prioritized if immediate remediation is not possible?
Prioritize workflows using Send and Wait with Approve Within Chat, especially where advancing the workflow triggers sensitive or consequential actions. The provided information does not specify a workaround beyond updating to a fixed version.