CVE-2026-86077: n8n: Anonymous Approval-Gate Bypass via Reused resumeToken over the Chat WebSocket

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-08 · updated 2026-09-14
Weakness: CWE-862

Description

n8n is an open source workflow automation platform. Prior to 2.37.7 and 2.38.2, the /chat WebSocket route accepted a resumeToken and resumed a paused execution without checking that the target node supported chat messages. An anonymous form submitter who received that token could reuse it on the chat route to release a Send-and-Wait, non-chat HITL, or Wait approval gate. The affected authorization logic is packages/cli/src/chat/chat-execution-manager.ts, where canResumeOverChat did not gate the resume target. This issue is fixed in versions 2.37.7 and 2.38.2.

Affected products

n8n-io n8n: before 2.37.7; from 2.38.0 before 2.38.2 — fixed in 2.37.7, 2.38.2

How to fix

Upgrade to a fixed version: n8n-io n8n 2.37.7, 2.38.2. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-86077 or the next vulnerability affects your stack