If you use the ChatGPT desktop app on macOS, you may have noticed an urgent update notification this week. It's not a routine feature drop. OpenAI is rotating security certificates after discovering that a malicious version of a widely used JavaScript library made its way into the company's build pipeline — a supply chain attack that could have compromised the digital signatures on several macOS applications.

Certificate Revocation and Update Timeline

On March 31, 2026 (UTC), OpenAI confirmed that a compromise of the Axios HTTP library had affected its macOS app signing process. A GitHub Actions workflow downloaded and executed the malicious version, Axios 1.14.1, during a build. This exposed the certificates and notarization credentials used to sign ChatGPT Desktop, Codex, Codex-cli, and Atlas — all macOS applications distributed by OpenAI.

OpenAI stated that it found no evidence the certificates were actually exfiltrated. But as a precaution, the company revoked the affected certificates and replaced them with new ones. Starting May 8, 2026, older versions of these apps signed with the old certificates will no longer be supported. macOS security policies will block them from launching entirely.

Supply Chain Response and Technical Changes

The root cause was a configuration error in the GitHub Actions workflow. Instead of pinning a specific commit hash, the workflow used a floating tag, and the minimum release age setting for new packages was missing. That allowed the malicious Axios version to slip into the build environment.

OpenAI worked with an external digital forensics firm to audit the notarization history of every piece of software signed with the old certificates. The investigation confirmed that no tampered software was distributed. Still, the company has redesigned its build environment to lock dependency versions and enforce stricter validation.

The most immediate change for developers and end users is the forced update mechanism. OpenAI recommends installing the latest version exclusively through the official website or the in-app updater. This incident is limited to macOS — iOS, Android, Linux, and Windows versions are unaffected. User passwords, API keys, and other personal data were not compromised.

After May 8, 2026, any macOS app signed with the old certificate will be blocked by macOS's built-in security protections. Users must switch to the latest version to close the security gap.

The trustworthiness of a software supply chain can collapse over a single library's version management policy. OpenAI's response shows that even when no actual damage is confirmed, the cost of inaction is higher than the cost of a forced migration.