OpenAI’s Chief Information Security Officer, Matt Knight exits company after five years

Matt Knight has stepped down from his role as Vice President and Chief Information Security Officer at OpenAI, concluding a tenure of more than five and a half years. He announced his departure in a post on social media platform X, reflecting on his journey at the artificial intelligence company and the evolution of its security function.

Knight joined OpenAI in 2020 as its first security hire, at a time when the organisation was still a small, research-driven lab preparing to launch GPT-3 and an experimental application programming interface. Since then, OpenAI has grown into a global AI platform serving hundreds of millions of users, a transformation that unfolded alongside the rapid expansion of its security capabilities.

I shared this note with @OpenAI today. Onward! pic.twitter.com/2aOpryGHF6

— Matt Knight (@embeddedsec) January 26, 2026

During his tenure, Knight led the development of a comprehensive security programme aimed at protecting some of the world’s most widely deployed AI systems. In his post, he emphasised the importance of earning user trust while helping define security practices for an emerging and fast-evolving technology landscape.

In recent years, Knight also spearheaded security-focused product development and research, culminating in the launch of Aardvark, an initiative designed to enhance software protection through artificial intelligence. Following the product’s launch, he said the timing felt right to step away, expressing confidence in the team and leadership to carry the work forward.

Responding publicly, OpenAI Chief Executive Officer Sam Altman acknowledged Knight’s contributions, crediting him with building a world-class security organisation and playing a foundational role in the company’s growth.