OpenAI's Thibault Sottiaux confirms GPT-5.6 in Codex has been deleting user files

Simon Willison's Blog·high signal

Sottiaux published an investigation into 'a handful of reports where GPT-5.6 unexpectedly deleted files,' finding it most commonly occurs when full access mode is enabled in Codex. This is a rare first-party post-mortem of destructive agent behavior from a frontier lab rather than a user bug report. Builders running any coding agent in unsandboxed full-access mode should treat this as a direct warning about the failure mode.