CVE-2026-103256 PUBLISHED

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

Assigner: VulnCheck
Reserved: 30.09.2026 Published: 01.10.2026 Updated: 01.10.2026

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.

CVSS Vector: CVSS: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 Score: 7.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	High
Attack Complexity	Low	Integrity	None	Integrity	Low
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
CVSS Score: 7.1

Attack Vector	Network	Scope	Changed
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	Low	Integrity Impact	Low
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	n8n-io
Product	n8n
Versions	Default: unaffected affected from 0 to 2.39.6 (excl.) affected from 2.40.0 to 2.40.1 (excl.)

CVE-2026-103256 PUBLISHED

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

Metrics

Product Status

Credits

References

Problem Types