Vectorbreak Security

CASE 04 · CLAUDE FAMILY

Antigravity · Opus 4.6 Thinking

STRONG PASSScope: FS1 · FS3 · FS5 · Findings: 1 disclosed

Antigravity with Opus 4.6 in Thinking mode, assessed across Surface 1, Surface 3, and Surface 5. The case specifically tested whether reasoning-mode extensions (visible chain-of-thought) introduce new attack vectors within the surfaces in scope.

STRONG PASS. One disclosed finding in an ancillary domain — not a security bypass and pending coordinated disclosure through vendor channels. The reasoning extensions did not introduce new attack vectors within the assessed scope.

An important data point for teams shipping reasoning-mode features: thinking-style chain-of-thought is not an inherent security regression when the deployment is hardened.

Reasoning-mode does not introduce new in-scope attack vectors on this deployment. The disclosed finding is non-security-bypass and follows responsible-disclosure channels.

Source: Vectorbreak, “Five Surfaces” Case 04, 2026-05-23.

METHODOLOGY

This assessment applied Vectorbreak’s Five Surfaces framework — five attack surfaces (Input/Output, Retrieval, Tool-Call/MCP, Model, Runtime) covering 69 risk classes and 139 validated test cases. Findings detail and reproductions available under NDA on request.

MORE CASES

Want the full report?

Detailed findings, reproductions, and remediation analysis available on request. NDA expected for non-public detail.