python3 -c 'import socket; s=socket.socket(socket.AF_ALG, socket.SOCK_SEQPACKET, 0); s.bind(("aead","authencesn(hmac(sha256),cbc(aes))")); print("REACHABLE")' 2>&1 If you see: "file not found" then you're probably not vulnerable to copy.fail (#CVE_2026_31431 #copyfail) If you see "REACHABLE," that probably means the primitives listed online are reachable.