CVE-2025-66405: Portkey Gateway

Critical severity, CVSS 9.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Portkey.ai Gateway is a blazing fast AI Gateway with integrated guardrails. Prior to 1.14.0, the gateway determined the destination baseURL by prioritizing the value in the x-portkey-custom-host request header. The proxy route then appends the client-specified path to perform an external fetch. This can be maliciously used by users for SSRF attacks. This vulnerability is fixed in 1.14.0.

Affected products

• Portkey Gateway: before 1.14.0 (fixed in 1.14.0)

Published 2025-12-01. Last modified 2026-06-17.