How severe is CVE-2025-66405?

No CVSS score has been assigned to CVE-2025-66405 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-66405?

CVE-2025-66405 affects the following packages: @portkey-ai/gateway (npm). Ecosystems affected: npm.

How do I fix CVE-2025-66405?

Update @portkey-ai/gateway to 1.14.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-66405 is resolved across your whole dependency graph.

How do I detect CVE-2025-66405 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @portkey-ai/gateway, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-66405 if there is no patch (or I can't update yet)?

Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Is CVE-2025-66405 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-66405 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-66405?

CVE-2025-66405 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 34th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-66405?

CVE-2025-66405 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2025-66405 published, and has it been updated?

CVE-2025-66405 was published on December 1, 2025 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2025-66405 — @portkey-ai/gateway

Fix: Portkey-AI/gateway@b5a7825

CVE-2025-66405 is a Server-Side Request Forgery (SSRF) vulnerability in @portkey-ai/gateway. A fix is available for @portkey-ai/gateway — see the affected versions and patch details below.

Portkey.ai Gateway: Server-Side Request Forgery (SSRF) in Custom Host

Also known asGHSA-hhh5-2cvx-vmfp

Published

Dec 1, 2025

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-66405.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs34th percentile — riskier than 34% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

1other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@portkey-ai/gatewaynpm

712downloads / week

Description

Summary

The gateway determines 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 (CWE-918) attack

Impact

This vulnerability can be exploited to force the server to make requests to arbitrary hosts on the internal network. This could allow an attacker to exfiltrate sensitive data, for instance, by accessing the AWS metadata service.

Patches

The issue is patched in 1.14.0 (https://github.com/Portkey-AI/gateway/pull/1372)

The vulnerability resides within the gateway's request processing function which handles the x-portkey-custom-host header. This parameter was passed directly or with insufficient validation/sanitization to an internal HTTP request function.

The fix (v1.14.0) implements a robust allow-list policy:

All custom host inputs are now strictly validated to ensure the resulting URI points only to trusted, expected external services.
The implementation now explicitly blocks requests to non-routable IP addresses, loopback addresses, private networks and standard metadata endpoints.

Credit

This vulnerability was discovered and reported responsibly by @im-soohyun. We thank them for their adherence to coordinated vulnerability disclosure principles.

References

https://cwe.mitre.org/data/definitions/918.html

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@portkey-ai/gateway`	all versions	1.14.0`npm install @portkey-ai/gateway@1.14.0`

Affected Products

1 product · 1 configurations

Application

gatewayportkey

< 1.14.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @portkey-ai/gateway, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @portkey-ai/gateway to 1.14.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-66405 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Frequently Asked Questions

### Summary The gateway determines 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 (CWE-918) attack ### Impact This vulnerability can be exploited to force the server to make requests to arbitrary hosts on the internal network. This could allow an attacker to exfiltrate sensitive data, for instance, by accessing the AWS metadata service. ### Patches The issue is patched in 1.14.0 (https://github.com/Portkey-AI/gatew

O3 Security · Impact-Aware SCA

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