How severe is CVE-2025-66405?

CVE-2025-66405 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-66405 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-66405?

CVE-2025-66405 affects Portkey Gateway. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-66405?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-66405 have an EU (EUVD) identifier?

Yes. CVE-2025-66405 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200120.

When was CVE-2025-66405 published?

CVE-2025-66405 was published on 2025-12-01 and last updated on 2026-06-17.

CVE-2025-66405

CVE-2025-66405 is a critical-severity vulnerability in Portkey Gateway with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-918.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 6.9
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-200120
Weakness: CWE-918
Affected product: Portkey Gateway
Published: 2025-12-01
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2025-66405?: CVE-2025-66405 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-66405 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66405?: CVE-2025-66405 affects Portkey Gateway. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-66405?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-66405 have an EU (EUVD) identifier?: Yes. CVE-2025-66405 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200120.
When was CVE-2025-66405 published?: CVE-2025-66405 was published on 2025-12-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:portkey:gateway:*:*:*:*:*:*:*:*

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