---
id: CVE-2026-103259
title: >-
  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
summary: >-
  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' sessi…
severity: high
cvss: 7.6
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H'
cwe:
  - CWE-863
vendor: n8n-io
product: n8n
affected:
  - n8n < 2.39.6
  - n8n >= 2.40.0 < 2.40.1
published: '2026-10-01'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T11:17:20.610'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-103259'
references:
  - url: 'https://github.com/n8n-io/n8n/security/advisories/GHSA-rx55-8qhx-4hwx'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/n8n-before-2.39.6-and-2.40-x-before-2.40.1-session-token-leak-via-dynamic-credentials
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-01T11:42:53.803Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.