CVE-2026-14537Authorization Bypass in MCP Toolbox Legacy HTTP Endpoints

Incorrect Authorization in the direct HTTP API tool invocation endpoint in Google mcp-toolbox versions v1.3.0 and v1.4.0 allows an unauthenticated attacker to invoke tools protected by the scopeRequired feature via sending tool invocation requests through legacy HTTP endpoints when the --enable-api flag is active.

8.1 HIGHEPSS 0.25%Not in KEVNVD: Analyzed

Last updated: 2026-10-23 23:10 UTC

OverviewCVSS details

8.1HIGHCVSS 4.0

Score source: Google (CNA)
NVD status: Analyzed
Published: Jul 31, 2026
Assigner: Google

Affected

mcp-toolbox (Google)

Versions: 1.3.0 · v1.4.0

Exploitation

Public exploit: None listed
CISA KEV: Not listed
KEV due date: —
SSVC: Exploitation none · Automatable yes · Impact total

EPSS · FIRST, scored Nov 8

0.25%chance of exploitation in 30 days

Higher than 16.72% of CVEs

CVSS 4.0 · Google (CNA)

8.1High

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: None
User interaction: None
Confidentiality impact: High
Integrity impact: High
Availability impact: High
Confidentiality (other systems): None
Integrity (other systems): None
Availability (other systems): None

CVSS 3.1 · NVD

9.8Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

NVD status: Analyzed

Overview Affected Products References

NVD CVE.org

Overview

Severity

Score	Severity	Version	Vector String
8.1	HIGH	4.0Google (CNA)	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U
9.8	CRITICAL	3.1NVD	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CVE ID: CVE-2026-14537
Status: Analyzed
Assigner (CNA): Google
Published: Jul 31, 2026
Last modified: 2026-10-23 23:10 UTC
Weaknesses: CWE-863 · (Incorrect Authorization)

Sources

Refreshed hourly from the sources above. Last fetched 2026-11-09 09:24 UTC.