WRITEUP — Kylian Nézan

WRITING

All publications.

All 5 CTF 1 EXPERIMENT 1 HACKATHON 1 WRITEUP 2

OPTAVIM: building a complete company information system

The full information system of a fictional multi-site company, built from scratch: from the HA pfSense firewall to the business apps, with a hand-built kubeadm Kubernetes cluster, Active Directory, a Keycloak SSO and 2FA. Security thought through from the start.

WRITEUP 5 min

06/04/26

GitHub Actions: from tag hijacking to the impostor commit

I replayed a full supply chain attack against a GitHub Actions pipeline, end to end. Mutable tags, SHA pinning, impostor commit: what actually protects you, and what falls short.

WRITEUP 6 min