ChatGPT Mac client fixes process trust chain bypass vulnerability

The ChatGPT Mac client fixed a vulnerability that could bypass process signature verification. OpenAI released the fix on September 25 and thanked researcher Patrick Wardle in the changelog. The poster stated that the vulnerability is numbered CVE-2026-100754 and the fixed version is 26.924.20706. When communicating between internal components, the client verifies that the calling process is signed by OpenAI and traces up to the parent and grandparent processes. The researcher found that a script interpreter bundled with and trusted by ChatGPT can be nested to launch three levels deep, making the malicious code's process chain appear as trusted OpenAI components in all three upward checks, thus passing verification. The poster said the attack code is about a dozen lines, and once bypassed, it can read chat history and gain computer permissions using ChatGPT's identity. The post also cites the author's own earlier post, arguing that macOS is tightening Full Disk Access to prevent AI agents from reading files, emails, Messages, browsing history, configuration, and logs.