Improper Verification of Cryptographic Signature in n8n - CVE-2026-118679
Published: November 9, 2026 / Updated: November 10, 2026
Vulnerability identifier: #VU163085
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-118679
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows an unauthenticated remote attacker to steal a Slack workspace access token and read responses from attacker-selected destinations.
The vulnerability exists due to fail-open signature verification in the n8n Slack Trigger webhook when its signing secret is absent and file downloading is enabled. An unauthenticated remote attacker can send a forged request to a known webhook URL, triggering a download that forwards the token to an attacker-controlled host and returns its response.
Affected software
n8n
How to mitigate CVE-2026-118679
Install security update from vendor's website.
n8n - addressed in versions 1.123.83, 2.41.4, 2.42.1