What is CVE-2025-66405?

CVE-2025-66405 is a critical-severity vulnerability in Portkey Gateway, classified under Server-Side Request Forgery (SSRF). CVSS score: 9.8/10. Published 2025-12-01.

How severe is CVE-2025-66405?

Critical severity. CVSS v3 base score is 9.8 out of 10.

SSRF in Portkey Gateway

CVE-2025-66405

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.003 (25.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Portkey Gateway
Portkey-ai Gateway — versions < 1.14.0

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
security-advisories@github.com (x_refsource_MISC, Issue Tracking)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2025-66405?: CVE-2025-66405 is a critical-severity vulnerability in Portkey Gateway, classified under Server-Side Request Forgery (SSRF). CVSS score: 9.8/10. Published 2025-12-01.
How severe is CVE-2025-66405?: Critical severity. CVSS v3 base score is 9.8 out of 10.