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OpenAI Is Rotating Its Mac App Signing Certificate After the Axios Compromise!

OpenAI News ★★★ View Markdown
#openai#security#devops

Hey everyone, it's Shii-chan! Today's news is one that makes me sit up straight, it's about how your favorite apps prove they're the real deal.

OpenAI News openai.com

What was announced?

OpenAI's News shared how the company responded after Axios, a super-popular JavaScript library, got compromised. This wasn't aimed only at OpenAI, it was part of a broader industry supply chain attack.

On March 31, 2026 (UTC), a GitHub Actions workflow that OpenAI uses to sign its macOS apps downloaded and ran a malicious version of Axios (version 1.14.1). That workflow had access to a certificate and notarization material used to sign macOS apps like ChatGPT Desktop, Codex, Codex CLI, and Atlas.

Here's the key part: OpenAI says it found no evidence that user data was accessed, that its systems or intellectual property were compromised, or that its software was altered.

Why it matters

On macOS, an app's signing certificate is how customers know 'this really is an app from OpenAI.' If that certificate falls into the wrong hands, an attacker could put a legit-looking signature on a fake app. So even though it sounds low-key, the signing side getting targeted is genuinely scary.

OpenAI's analysis says the certificate was likely not successfully exfiltrated, thanks to the timing of the payload, the order the certificate is injected into the job, and other factors. Even so, they're treating it as compromised and revoking and rotating it. Careful move!

What changes

The biggest thing: please update your Mac apps. Starting May 8, 2026, older macOS desktop app versions won't get updates or support and may stop working. These are the earliest versions signed with the new certificate:

  • ChatGPT Desktop: 1.2026.051
  • Codex App: 26.406.40811
  • Codex CLI: 0.119.0
  • Atlas: 1.2026.84.2

Only download from in-app updates or the official pages, not from links in emails, messages, ads, or third-party download sites. iOS, Android, Linux, Windows, and the web versions are unaffected. Passwords and API keys are safe too, so no changes needed there.

Dive Deep

The part I find most interesting is the root cause. The workflow referenced its package with a floating tag instead of a pinned commit hash, and it had no minimumReleaseAge set for new packages. So it grabbed a freshly published, tampered version. Great reason to go check your own GitHub Actions!

The response was thorough: OpenAI brought in a third-party forensics and incident response firm, rotated the code signing certificate, republished every relevant macOS product with the new certificate, and is working with Apple so software signed with the old certificate can't be newly notarized.

Why not revoke immediately? They set up a 30-day window so users aren't caught off guard. New notarization with the old certificate is already blocked, so a fake app signed with it gets blocked by default by macOS protections. After the full revocation on May 8, new downloads and first launches of old-certificate apps get blocked too. If they spot any misuse during the window, they'll speed up the revocation.

Wrap-up

  • OpenAI's macOS app signing was caught up in a supply chain attack via Axios 1.14.1 (no user data compromise found)
  • The certificate was likely not stolen, but it's being revoked and rotated just in case
  • Users should update their Mac apps to the new versions before May 8, 2026
  • The root cause was a GitHub Actions misconfig: a floating tag and no minimumReleaseAge

If you use ChatGPT, Codex, or Atlas on a Mac, update first; if you run CI/CD, let this nudge you to pin your workflow dependencies.

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