CVE-2026-77069: n8n

Medium severity, CVSS 4.3. EPSS: 0.3% chance of exploitation in the next 30 days.

n8n before 1.123.69, 2.33.4, and 2.34.1 contains an SSRF protection bypass in the OAuth2 credential authorization-code-to-access-token exchange. While OAuth2 discovery and dynamic-client-registration requests use n8n's SSRF-protected HTTP client, the token exchange uses a separate client with no SSRF guard. A user with credential-creation permissions can set the access-token URL to an internal address and complete the OAuth2 flow, causing n8n to send a fixed-shape token-exchange POST to that target and reflect its response body back to the attacker (limited to what the target returns to this specific request).

Affected products

• n8n n8n: before 1.123.69 (fixed in 1.123.69); from 2.33.0, before 2.33.4 (fixed in 2.33.4); version 2.34.0 only

Published 2026-08-20. Last modified 2026-09-01.