CVE-2026-103259

High

Description

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.

SeverityHigh

CVSS7.6

Exploit probability—

ProductN8n

PublishedOct 1, 2026

First seenOct 1, 2026

Weakness typeCWE-863Incorrect authorization

How to fix

Update

n8n-io n8n2.39.6, 2.40.1 or later

Vendor advisories

github.com/n8n-io/n8n/security/advisories/GHSA-rx55-8qhx-4hwx

Affected products

Product	Affected versions	Fixed in
n8n-io n8n	v < 2.39.6, 2.40.0 ≤ v < 2.40.1	2.39.6, 2.40.1

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