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Cross-platform C port of the Copy Fail Linux LPE (CVE-2026-31431). Disclosed 2026-04-29 by Theori / Xint.

424 starsC

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

by tgies·Apr 30, 2026·4 points·0 comments
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AI Analysis

●●●BangerWizardryBig Brain

Porting a complex page-cache mutation exploit to pure portable C with zero assembly is impressive constraint craft.

Strengths
  • •Uses nolibc to eliminate architecture-specific hex blobs or inline assembly.
  • •Includes a non-destructive checker alongside the destructive exploit variants.
  • •Demonstrates the AF_ALG splice primitive mutation in clean, readable C.
Weaknesses
  • •Niche utility limited to those studying this specific CVE or kernel primitives.
  • •Relies on the very recent 2026 disclosure, limiting historical context.
Category
Security
Target Audience

Security researchers and kernel hackers

Similar To

Theori/Xint Copy Fail PoC · pwntools

Post Description

This is a C port of Theori/Xint's Copy Fail PoC (https://copy.fail/, 2026-04-29). The original depended on Python and embedded x86_64 shellcode. I managed to reimplement the shellcode as portable C using nolibc borrowed from the kernel, and now the whole thing can be compiled for & works on any arch supported by nolibc.

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