K3ysTr0K3R/CVE-2026-31431-EXPLOIT

# CVE-2026-31431 - Copy Fail This vulnerability allows an **unprivileged local attacker** to gain **root privileges** on a vulnerable Linux system. ## ⚠️ DISCLAIMER This code is provided **for educational and security research purposes only**. It demonstrates a hypothetical vulnerability (CVE-2026-31431) in the Linux kernel's `AF_ALG` socket interface. Do **not** run this on any system you do not own or have explicit written permission to test. Misuse of this code may violate laws and regulations. ## 📜 Description **CVE-2026-31431** (disclosed 2026) is a **copy-on-write / length confusion** bug in the authencesn(hmac(sha256),cbc(aes)) AEAD implementation. By crafting specific `sendmsg()` control messages with zero-length buffers, an attacker can trigger a kernel `splice()` operation to overwrite adjacent memory pages – leading to arbitrary file corruption. This PoC targets `/usr/bin/su` to modify its binary payload in 4‑byte chunks, then executes it to demonstrate privilege escalation. ## 🚀 Features - Abuses `AF_ALG`, `SOL_ALG` socket options - Uses `splice()` + `sendmsg()` for zero‑copy data transfer - Decompresses and writes a hidden payload - Colored terminal output (green author tag / blue execution)