Claude Code’s Network Sandbox Vulnerability Exposes User Credentials and Source Code

Anthropic’s Claude Code had a critical SOCKS5 hostname null-byte injection vulnerability in its network sandbox from v2.0.24 through v2.1.89 (≈Oct 20, 2025–Apr 1, 2026) that allowed attackers to bypass allowlists and exfiltrate AWS credentials, GitHub tokens, cloud metadata, internal endpoints, environment variables, and model API keys. The issue was privately patched in v2.1.90 without a public advisory or CVE; users are advised to update immediately, audit SOCKS egress logs, and rotate reachable credentials.