Copy Fail is 732 bytes. Your foothold problem is the bigger one.

CVE-2026-31431 dropped this week. The disclosure site is at copy.fail and the writeup is short enough to read with coffee. The TL;DR: a logic flaw in the kernel's authencesn path, reachable through AF_ALG sockets, abused via splice() to land a 4-byte write into the page cache of any setuid binary. T