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Verified reproduction

CVE-2026-14537: mcp-toolbox authorization bypass: unauthenticated tool invocation via direct HTTP API

CVE-2026-14537 is verified against googleapis/genai-toolbox · github affected versions: >= v1.3.0 (2026-05-21) and <= v1.4.0 (2026-06-04) fixed version: v1.5.0 (2026-06-18) vulnerability class: Auth Bypass This high reproduction includes runnable sandbox proof, artifacts, and a plain-text agent view under REPRO-2026-00318.

REPRO-2026-00318 googleapis/genai-toolbox · github Auth Bypass Aug 1, 2026 CVE entry .txt
Severity HIGH
Confidence HIGH
Reproduced in 37m 46s
Tool calls 197
Spend $4.34
Affected >= v1.3.0 (2026-05-21) and <= v1.4.0 (2026-06-04)
Fixed in v1.5.0 (2026-06-18)
$ pruva-verify REPRO-2026-00318
or curl -O https://pruva.dev/api/v1/reproductions/REPRO-2026-00318/artifacts/bundle/repro/reproduction_steps.sh && chmod +x reproduction_steps.sh && ./reproduction_steps.sh
Run in a VM or disposable container. This exploits a real vulnerability.
02 · The vulnerability

Incorrect authorization in google/mcp-toolbox v1.3.0–v1.4.0 (CWE-863, CVSS 4.0 8.1). Affected versions: >=1.3.0 (2026-05-21) and <=1.4.0 (2026-06-04); fixed in v1.5.0 (2026-06-18).

03 · Root cause
04 · Reproduction transcript

The agent's step-by-step process — every tool call, every handoff, the moment the exploit fired.

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05 · Artifacts

Scripts, logs, diffs, and output captured during the reproduction.