CVE-2026-103259

8.5 highEPSS 0.2%

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 4.0: 8.5CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:A/VC:H/VI:H/VA:H/SC:H/SI:L/SA:N
CVSS 3.1: 7.6CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H
EPSS: 0.2% chance of exploitation in the next 30 days; higher than 14% of CVEs (scores of 2026-10-25)
CWE: CWE-863
Published: 2026-10-01
Modified: 2026-10-01
Record from: the NVD, synced 2026-10-19

References

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