Show HN: Copy-fail-C – portable C port of CVE-2026-31431, with a checker

Category: security

Tags: exploit, linux, cve, portable-c, nolibc

Score: 7.0/10 (Innovation: 6, Technical: 9, Documentation: 8, Utility: 5)

A portable C reimplementation of the CVE-2026-31431 Linux LPE exploit, demonstrating a novel page-cache mutation primitive using AF_ALG and splice(). It includes both a binary-mutation variant for setuid binaries and a /etc/passwd UID-flip variant, along with a non-destructive vulnerability checker, all compiled to a tiny ELF using nolibc.

Target audience: security researchers, kernel developers, devops

Repository: https://github.com/tgies/copy-fail-c · C · NOASSERTION · 108 stars

View on Hacker News