CVE-2026-14541Network attack vector

Unauthorized tool access via skipped audience validation

Published Jul 31, 2026 · Updated Jul 31, 2026

Authentication bypass in Google MCP Toolbox for Databases 1.4.0 allows remote attackers to access protected tools and data. ValidateMCPAuth accepts opaque Google access tokens without checking their audience when mcpEnabled is true and neither audience nor clientId is configured. Exploitation requires any valid Google OAuth access token and the affected non-default authentication configuration, granting access to the instance's protected tools and connected data backends.

CVSS severityUnavailable
Unscored
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Authentication bypass in Google MCP Toolbox for Databases 1.4.0 allows remote attackers to access protected tools and data. ValidateMCPAuth accepts opaque Google access tokens without checking their audience when mcpEnabled is true and neither audience nor clientId is configured. Exploitation requires any valid Google OAuth access token and the affected non-default authentication configuration, granting access to the instance's protected tools and connected data backends.

The record

CVE
CVE-2026-14541
Published
Jul 31, 2026
Updated
Jul 31, 2026
Vendor
Go standard library
Product
MCP Toolbox for Databases
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go standard library · MCP Toolbox for Databasesversion=1.4.0

Published CVSS scores

8.0National Vulnerability DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo