That mainstream deployment shaped user expectations in a way that later transitions struggled to accommodate. In August 2025, when OpenAI initially replaced GPT-4o with its much anticipated then-new model family GPT-5 as ChatGPT’s default and pushed 4o into a “legacy” toggle, the reaction was unusually strong.

Mixpanel first detected the unauthorized access on Nov. 9, 2025. Investigators later confirmed that an attacker had exported a dataset containing customer-identifiable metadata. The provider supplied OpenAI with the impacted dataset on Nov. 25, enabling a detailed examination of the information exposed.

The breach occurred within Mixpanel’s systems and exposed only limited analytics-level data linked to API accounts, OpenAI has said in an email to users

According to OpenAI, GPT-5.2 sets a number of new highs across several benchmarks and supposedly “outperforms industry professionals at well-specified knowledge work tasks spanning 44 occupations.” In its “Thinking” mode,

ChatGPT maker places other vendors under review following breach OpenAI says API users may be affected by a recent breach at its former data analytics provider, Mixpanel.… Limiting the exposure somewhat,

Mixpanel’s namesake analytics platform enables companies to collect data about how users interact with their applications. The software tracks metrics such as customer retention, uptime and performance. At the time of the breach, OpenAI used Mixpanel to collect data about developer interactions with its application programming interfaces.

Artificial intelligence (AI) company OpenAI was impacted by a third-party breach affecting analytics company Mixpanel, exposing “limited” user data.

OpenAI has revealed a data breach at third-party vendor Mixpanel, potentially exposing personal details of its API platform users.

Revealed on Thanksgiving Eve, the incident serves as a reminder that we're all responsible for exploring additional security options.

For the first time, developers can embed Google's Deep Research tool, based on Gemini 3 Pro, into their own apps.