o3 returns to ChatGPT
OpenAI put the o3 model back into the ChatGPT model picker for paid users and added a web toggle labeled “Show additional models” that surfaces options like o3 and GPT‑5 Thinking mini. (help.openai.com) Separately, OpenAI said it is rotating potentially exposed macOS code‑signing certificates after a third‑party Axios package supply‑chain incident and urged all Mac app users to update, saying user data was not accessed. (bleepingcomputer.com) (claimsjournal.com)
OpenAI has put o3 back into ChatGPT for paid users while telling every macOS app user to update after a software supply-chain scare. (help.openai.com) (openai.com) In OpenAI’s ChatGPT release notes, the company said paid users now have a “Show additional models” setting on the web that surfaces extra options in the model picker, including o3 and GPT-5 Thinking mini. The help page was updated on April 14, 2026. (help.openai.com) That change partially reverses OpenAI’s February 13, 2026 retirement of several ChatGPT model options, when the company said GPT-4o, GPT-4.1, GPT-4.1 mini, OpenAI o4-mini, and GPT-5 Instant and Thinking had been removed from ChatGPT. (help.openai.com 1) (help.openai.com 2) The model-picker shift comes as OpenAI keeps steering most users toward a simpler default system. In a separate help article updated April 12, OpenAI said GPT-5.3 Instant is now the default for logged-in users, with ChatGPT able to auto-switch to GPT-5.4 Thinking on harder requests. (help.openai.com) At the same time, OpenAI said on April 10 that a compromised version of Axios, a widely used developer library, ran inside a GitHub Actions workflow used in its macOS app-signing process on March 31, 2026. That workflow had access to a certificate and notarization material for ChatGPT Desktop, Codex, Codex command-line interface, and Atlas. (openai.com) Code-signing certificates are the digital stamps that tell a Mac an app really came from a named developer. OpenAI said it found no evidence that user data was accessed, that its systems or intellectual property were compromised, or that its shipped software was altered. (openai.com) (bleepingcomputer.com) OpenAI said it is revoking and rotating the affected certificate “out of an abundance of caution” and that all macOS users need the latest app versions. The company said older versions of its macOS desktop apps may stop working and will no longer receive updates or support after May 8, 2026. (openai.com) The earliest macOS releases signed with the new certificate are ChatGPT Desktop 1.2026.051, Codex App 26.406.40811, Codex command-line interface 0.119.0, and Atlas 1.2026.84.2. OpenAI also said it reviewed notarization activity tied to the old certificate and found no unexpected software notarization. (openai.com) For companies that allow or block Mac apps by certificate, OpenAI said the Team ID stays the same at 2DC432GLL2, but the organization name and certificate fingerprint changed. The new organization name is “OpenAI OpCo, LLC,” replacing “OpenAI, L.L.C.” in the previous version. (help.openai.com) The two updates land on the same day with opposite messages: more model choice inside ChatGPT, and less tolerance for outdated Mac installs outside it. In both cases, OpenAI is pushing paid users and desktop users toward newer settings, newer builds, and tighter control over how its products are delivered. (help.openai.com) (openai.com)
