CVE-2026-16481

What it is

A Server-Side Request Forgery (SSRF) and credential exfiltration vulnerability exists in the cloud-healthcare-fhir-fetch-page tool of googleapis/mcp-toolbox. The tool takes an unvalidated pageURL parameter from the client and issues an HTTP GET request to it using an authenticated client. The underlying transport automatically attaches an Authorization: Bearer header to every outbound request regardless of the destination host. An attacker can supply an arbitrary external URL to the pageURL parameter (either directly via the tool execution payload or implicitly via data-driven pagination tracking loops), leading Toolbox into sending its OAuth/service-account access token to an attacker-controlled listener. Depending on the configuration, this leaks either the end-user's token or the broader service-account access token (ADC), potentially exposing Protected Health Information (PHI) and secondary Google Cloud Platform services.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-27 19:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-24 13:10 UTC Last updatedMost recent change to the record

Details

Published

2026-07-27 19:17 UTC

Last modified

2026-10-24 13:10 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-918 · Server-side request forgery

Record status

Analyzed

Affected

• Google Mcp Toolbox For Databases < 1.5.0

Attack profile CVSS 4.0 · 6.0

Attack vector

Network

Complexity

High

Attack requirements

None

Privileges needed

Low

User interaction

None

Confidentiality

High

Integrity

None

Availability

None