CVE-2026-103259: n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain a session token leakage vulnerability in the Dynamic Credentials authorize and revoke endpoints…

PriorityP340high7.6CVSS 3.1

AVNACHPRHUIRSCCHIHAH

EPSS

0.24%

13.7th percentile

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 contain a session token leakage vulnerability in the Dynamic Credentials authorize and revoke endpoints. Attackers with resolver registration capability can capture collaborators' session tokens by setting a fallback resolver to an attacker-controlled endpoint during the account connection flow, enabling unauthorized credential access.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
n8n-io	n8n	< 2.39.6	2.39.6
n8n-io	n8n	>= 2.40.0 < 2.40.1	2.40.1

CVSS provenance

nvdv3.17.6HIGHCVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H

nvdv4.08.5HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:A/VC:H/VI:H/VA:H/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

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