---
id: "CVE-2026-118679"
kind: "vulnerability"
aliases: ["CVE-2026-118679"]
title: "n8n: Slack Trigger webhook lets unauthenticated attackers steal Slack tokens"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: []
ecosystems: []
tags: ["ai-tooling", "n8n", "self-hosted", "slack", "workflow-automation"]
not_affected_if: ["managed-hosting", "no-slack-trigger", "signing-secret-set"]
published_at: "2026-10-28T19:17:34+00:00"
first_seen_at: "2026-10-28T19:34:55+00:00"
updated_at: "2026-10-28T19:36:00+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118679", "first_seen_at": "2026-10-28T19:34:55+00:00"}]
---

# n8n: Slack Trigger webhook lets unauthenticated attackers steal Slack tokens

n8n's Slack Trigger webhook skips signature checks when no signing secret is set, so anyone who knows the webhook URL can make it fetch an attacker-chosen file. The request sends the Slack workspace access token to the attacker's host, which exposes that token.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `n8n --version` (or check the n8n image tag) and compare against `1.123.83`, `2.41.4` and `2.42.1`.
- In each workflow, look for a Slack Trigger node and check whether a Slack signing secret is configured in its credentials.
- Confirm whether the n8n webhook URLs are reachable from the internet.

## Fix

- Upgrade n8n to `1.123.83` on the 1.x line, `2.41.4` on 2.41.x, or `2.42.1` on 2.42.x.
- Set a Slack signing secret on every Slack Trigger node until the upgrade is done.
- Rotate the Slack workspace access tokens used by n8n if the instance was exposed while unpatched.

## Timeline

- 2026-10-28T19:34:55+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118679

## From the sources

n8n before 1.123.83, 2.41.4, and 2.42.1 contains a server-side request forgery vulnerability in the Slack Trigger webhook that allows unauthenticated attackers to exfiltrate Slack tokens by bypassing signature verification when no signing secret is set. Attackers who know the webhook URL can name a file to download, causing the node to send the workspace access token to an attacker host and return the response.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_