by Kastro
Paper/Archive/CVE-2026-14537

CVE-2026-14537

Google mcp-toolbox — Authorization Bypass in MCP Toolbox Legacy HTTP Endpoints

EPSS 0.3%CVSS 9.8
critical.is priorityof 100
33
CVSS 9.8 (NVD)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 16.7.167 × 203.3No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
mcp-toolbox1.3.0–CNA
mcp-toolboxv1.4.0–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Google (CNA)8.1CVSS: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
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgithub.com/googleapis/mcp-toolbox/pull/3435