Claude Code Deny Rules Can Be Silently Bypassed

The article explains a critical vulnerability discovered by Adversa in Anthropic’s Claude Code, where built-in “deny rules” meant to block dangerous commands can be bypassed under specific conditions. Due to a hard limit of around 50 subcommands, the system stops enforcing security checks on longer command chains and falls back to a permissive approval flow. Attackers can exploit this by padding commands with harmless steps and hiding malicious actions at the end, enabling data exfiltration or command execution. The issue highlights how agent design tradeoffs—like performance and token limits—can quietly disable core security controls.

https://adversa.ai/blog/claude-code-security-bypass-deny-rules-disabled

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