CVE-2026-103256

n8n before 2.39.6 and 2.40.x before 2.40.1 Credentials Leak via preAuthentication Hook

7.1 High

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain a credentials leak vulnerability in the Wekan and Baserow username-and-password credentials that sends unencrypted passwords to unvalidated hosts. Attackers with credential update permissions can modify the host field to receive account passwords at arbitrary hosts, bypassing domain validation controls.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: None
Availability: None

Exploit likelihood

0.21%Unchanged since Oct 2, 2026

What each source reports

CVE List Score used 7.1

n8n before 2.39.6 and 2.40.x before 2.40.1 Credentials Leak via preAuthentication Hook

Record: CVE-2026-103256
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:L/SA:N
CVSS 3.1: 7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
Weakness: CWE-522
Updated: 2026-11-02

EUVDEUVD-2026-90650 7.1

Record: EUVD-2026-90650
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:L/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-6m32-557f-fqq9 7.1

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain a credentials leak vulnerability in...

Record: GHSA-6m32-557f-fqq9
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
Weakness: CWE-522
Updated: 2026-11-02

NVD 7.1

Record: CVE-2026-103256
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 7.1 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
Weakness: CWE-522
Updated: 2026-11-02

OSV 7.1

n8n before 2.39.6 and 2.40.x before 2.40.1 Credentials Leak via preAuthentication Hook

Record: CVE-2026-103256
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:L/SA:N
Weakness: CWE-522
Updated: 2026-11-02

Affected products

n8n-io n8n

History

History
Recorded	Changed	Sources
Nov 2, 2026	affected, aliases, facts
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-103256 is a high vulnerability (CVSS 7.1) in N8n-io N8n, published October 1, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. No source names a fixed version.