High severity · published Oct 1, 2026
CVE-2026-103259
n8n before 2.39.6 and 2.40.x before 2.40.1 Session Token Leak via Dynamic Credentials
7.6
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
High
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
N8
n8n · n8n-io
before 2.39.6; 2.40.0 before 2.40.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103259
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103259
vendor-advisory
https://github.com/n8n-io/n8n/security/advisories/GHSA-rx55-8qhx-4hwx
third-party-advisory
https://www.vulncheck.com/advisories/n8n-before-2.39.6-and-2.40-x-before-2.40.1-session-token-leak-via-dynamic-credentials
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