CVE-2026-77069

published 2026-08-20

CVE-2026-77069: 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…

Priority P4 26 medium 4.3 CVSS 3.1

AV N AC L PR L UI N S U C L I N A N

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

6 ranges

Vendor	Product	Version range	Fixed in
n8n-io	n8n	< 1.123.69	1.123.69
n8n-io	n8n	>= 2.0.0 < 2.33.4	2.33.4
n8n-io	n8n	>= 2.34.0 < 2.34.1	2.34.1
n8n	n8n	< 1.123.69	1.123.69
n8n	n8n	—	—
n8n	n8n	>= 2.33.0 < 2.33.4	2.33.4

CVSS provenance

nvd v3.1 4.3 MEDIUM CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

nvd v4.0 2.3 LOW CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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CWE-918