Update — May 12, 2026: The certificate revocation went live on schedule on May 8, 2026. If your ChatGPT, Codex, Codex CLI, or Atlas Mac app now refuses to open and shows a “damaged” or “cannot be verified” warning, this guide still works; the fastest fix is a fresh download from chatgpt.com/download, since the in-app updater is no longer reachable from any build signed with the revoked certificate.
On May 8, 2026, OpenAI revoked the macOS code-signing certificate it had used to sign ChatGPT, Codex, Codex CLI, and Atlas through April 2026. From that day on, macOS Gatekeeper refuses to launch any version still signed with the old certificate, so a familiar app icon throws a security warning instead of opening. The trigger was a March 31, 2026 supply chain attack on the popular axios npm library, which slipped into OpenAI’s GitHub Actions Mac signing pipeline and forced a full certificate rotation.
If your ChatGPT desktop client for Mac suddenly refuses to launch, this guide walks you through the 2-minute fix, the clean reinstall path when the in-app updater is no longer reachable, the version check that confirms you are on a safe build, what OpenAI says about your data, and the multi-model option some Mac users are picking up so they stop being on the hook for any single vendor’s signing pipeline. We also flag the simple version check most write-ups skip.
The Key Takeaways
- What broke and when. OpenAI revoked its old macOS code-signing certificate on May 8, 2026. ChatGPT, Codex, Codex CLI, and Atlas builds dated before April 20, 2026 stopped launching.
- The fix takes 2 minutes. If the app still opens, click ChatGPT → Check for Updates. If it doesn’t, reinstall from chatgpt.com/download.
- Safe versions are any builds released after April 20, 2026. Confirm via ChatGPT → About ChatGPT in the macOS menu bar.
- Only macOS is affected. Windows, iOS, Android, and chatgpt.com on the web are unaffected.
- No user data was accessed. OpenAI says no evidence its systems, user data, or software were altered, only the build pipeline was compromised. Multi-model alternatives like the Fello AI app for Mac are a backup if you want to stop relying on a single desktop client.
What Happened on May 8, 2026
OpenAI revoked the Apple-issued certificate it had used to sign all four of its Mac apps. Apple’s Gatekeeper, the security system at the heart of macOS, refuses to launch any app whose signature is no longer trusted. Once the certificate was revoked, every old build looked identical to a forged or tampered binary in the eyes of macOS, even though nothing on your Mac had changed.
The reason was a textbook supply chain attack. On March 31, 2026, attackers compromised the maintainer account of axios, an HTTP client library with roughly 100 million weekly downloads across the JavaScript ecosystem. Google’s Threat Intelligence Group attributed the operation to UNC1069, a North Korea-linked group. The attackers pushed a malicious version, 1.14.1, that briefly slipped into OpenAI’s GitHub Actions workflow used to sign Mac apps. OpenAI rotated the certificate out of caution, even though forensic analysis suggested the cert was likely never exfiltrated.
The clean fix is the new certificate. OpenAI re-signed every Mac app and started shipping new builds in mid-April 2026. As long as you are running a version released after April 20, 2026, you are signed with the new certificate and the app launches normally.
My ChatGPT Mac App Won’t Open: The Fix
If ChatGPT throws a Gatekeeper warning the moment you double-click the icon, the in-app updater is no longer reachable from your old build. The clean recovery path is a fresh install. Quit any running ChatGPT processes from Activity Monitor, drag the existing ChatGPT.app out of Applications to the Trash, and download the latest installer from chatgpt.com/download. The new build is signed with the rotated certificate and Gatekeeper accepts it on launch.
You will not lose your conversation history. ChatGPT history lives on OpenAI’s servers tied to your account, not in the app bundle. After reinstalling, sign back in and your chats are exactly where you left them.
If macOS still flags the new binary as damaged after a clean reinstall, your Keychain is probably caching the revoked certificate. Open Keychain Access, search for “OpenAI” or “ChatGPT”, delete any expired or revoked entries, and try the install again. This is rare but happens on machines that were running multiple old builds.
How to Update Your ChatGPT Mac App in Under Two Minutes
If your ChatGPT app still opens, the fastest way to get back on a safe build is from inside the app itself. Launch ChatGPT, click ChatGPT in the macOS menu bar at the top-left of your screen, and pick Check for Updates. If a new version is available, install it and let the app restart. If you see a banner inside ChatGPT prompting you to update, that does the same thing.
A manual download works as a fallback if the in-app updater fails or the app already refuses to open.
- Quit the ChatGPT app on Mac.
- Open Safari (or any browser) and go to chatgpt.com/download.
- Download the latest ChatGPT for macOS installer.
- Drag ChatGPT.app into your Applications folder, replacing the old version when prompted.
- Launch it from Applications. The first launch may take a few extra seconds while macOS verifies the new signature.
If you want to confirm you are on a safe build, click ChatGPT → About ChatGPT in the menu bar. The version date should be on or after April 20, 2026. Anything earlier is signed with the revoked certificate.
The macOS desktop app requires macOS 14 or newer and Apple Silicon (M1 or better). Intel Macs and older macOS releases are not supported by the official OpenAI client, which is a separate question from this certificate issue.
What You Might See, and How to Read It
The symptom you see depends on which build you were running when you last launched the app. The table below covers the four most common scenarios after the May 8 revocation.
| Symptom | Likely cause | What to do | Time required |
|---|---|---|---|
| App opens normally; no warnings | You are already on a safe build (post-April 20, 2026) | Nothing; confirm via About ChatGPT | ~10 seconds |
| App opens but updater stuck | Build is recent enough to launch but cannot fetch updates | Quit, reinstall fresh from chatgpt.com/download | ~3 minutes |
| “ChatGPT is damaged and can’t be opened” | Build is signed with the revoked certificate | Reinstall from chatgpt.com/download; do not bypass Gatekeeper | ~3 minutes |
| “ChatGPT cannot be verified” | Same as above; Gatekeeper rejects the old signature | Same fix; reinstall fresh, do not right-click-Open the old binary | ~3 minutes |
The Gatekeeper warning is alarming the first time you see it. It uses the same wording macOS uses for actually malicious binaries, which is exactly why OpenAI rotated the certificate. Any app signed with that cert had to come down with it. Avoid the temptation to right-click and “Open Anyway”; the cleaner move is the fresh install, which puts you on a Mac app that Apple’s notarization service still trusts.
All Four OpenAI Mac Apps Are Affected
The certificate change was not just a ChatGPT problem. The same OpenAI signing pipeline issued the certificates for every Mac app the company ships. If you have any of the following installed, each one needs the same update.
ChatGPT Desktop is the consumer-facing client most people on FelloAI use. It is the highest-volume app affected and the one you are most likely to see in your Applications folder.
Codex is OpenAI’s coding-focused desktop client. If you write code with it on Mac, it needs the same update path as ChatGPT.
Codex CLI is the terminal tool many developers wire into shell scripts. The May 8 revocation hits CLI binaries the same way it hits the GUI apps; reinstall via brew or whatever package manager you used originally.
Atlas is the OpenAI browsing client. Less common on Mac than the other three, but if it is installed it follows the same fix.
Do not assume that because ChatGPT updated cleanly, the others did. Each app maintains its own update channel, so confirm each one separately.
Was My ChatGPT Data Compromised?
OpenAI’s official advisory on the Axios incident is direct on this point. The company writes that it “found no evidence that OpenAI user data was accessed, that our systems or intellectual property was compromised, or that our software was altered.” The compromise hit the build pipeline, not the production servers, and the certificate rotation was a precautionary control to make sure nobody can sign a fake “OpenAI” Mac app using the leaked credentials in the future.
Independent reporting from The Hacker News and BleepingComputer corroborates that read; both note OpenAI engaged a third-party digital forensics firm and that no production systems showed signs of compromise. You can read OpenAI’s own writeup on its Axios developer tool compromise advisory.
That is good news for your account, your billing, and your stored conversations. The bad news is that supply chain attacks on developer tooling are becoming common enough that this won’t be the last one, which is the broader point worth thinking about.
Why This Keeps Happening, and a Multi-Model Alternative
Single-vendor desktop clients are fragile by design. When one company controls the signing certificate, the auto-updater, and the model behind your chat, any one of those breaking takes the whole product down with it. ChatGPT has gone through outages, login issues, model deprecations, and now a certificate revocation in the past 12 months alone. Most Mac users patch each one and move on. That works fine until you hit a workday where the app will not launch, and the work piling up on your desk does not care why.
If you want a backup, the Fello AI app for Mac is a Mac and iOS client that bundles ChatGPT, Claude, Gemini, Grok, and DeepSeek under one $9.99/month subscription. The point is not to replace ChatGPT. The point is that one vendor’s signing issue stops being your problem when you can switch models inside the same app and keep working. It is the same logic many teams use for cloud providers; redundancy beats reliability claims. If you want background on how those models compare, our best AI models in 2026 roundup covers the trade-offs in detail.
For Mac users specifically, our guide to the best ChatGPT alternatives for Mac rates the multi-model clients side by side, including how each one handles outages, model switching, and pricing.
Conclusion
The May 8 revocation is recoverable in two minutes if your app still opens, and in three minutes if it doesn’t. Either way, your data is fine and your account is fine. The longer-term takeaway is the one most security-news sites skipped. Single-vendor desktop clients fail in single-vendor ways, and a single bad cert rotation can take an entire workflow down with it. If your workflow can survive a one-day ChatGPT outage, do nothing past clicking Check for Updates. If it can’t, line up a multi-model fallback before the next one of these inevitably lands.
If you want to compare the native Mac clients head to head, our Claude AI desktop client for Mac and Gemini desktop app for Mac pages cover the two strongest alternatives in detail.
FAQ
My ChatGPT Mac app won’t open. What do I do?
Open Safari, go to chatgpt.com/download, drag the new ChatGPT.app into Applications (replacing the old one), and launch it from Applications. The new build is signed with the rotated certificate, so Gatekeeper will accept it. Your conversation history lives on OpenAI’s servers and will be intact when you sign in.
What version of ChatGPT for Mac is safe?
Any build released after April 20, 2026. You can confirm by clicking ChatGPT → About ChatGPT in the macOS menu bar. Builds dated earlier are signed with the revoked certificate and stopped launching on May 8.
Are Windows, iOS, or web ChatGPT users affected?
No. The certificate revocation is specific to macOS code signing. Windows, iOS, Android, and chatgpt.com on the web are unaffected.
Was my ChatGPT account or data compromised?
OpenAI states no evidence of user data access or system compromise. The Axios attack hit OpenAI’s Mac app build pipeline; the certificate was rotated as a precaution, not in response to confirmed exfiltration.
Can I keep using ChatGPT without updating the Mac app?
If you don’t want to reinstall, you can use ChatGPT on the web at chatgpt.com, on iOS, on Android, or through any third-party Mac client (such as the Fello AI app for Mac) that talks to OpenAI’s API rather than the official desktop binary.
Did OpenAI extend the May 8 deadline?
No. The certificate revocation went live on May 8, 2026 as announced. If your app was on an old build, it stopped launching on that date and the fix is the fresh download from chatgpt.com/download.
