OpenAI–Anthropic cross-tests expose jailbreak and misuse risks — what enterprises must add to GPT-5 evaluations

OpenAI and Anthropic may often pit their foundation models against each other, but the two companies came together to evaluate each other’s public models to test alignment. 

The companies said they believed that cross-evaluating accountability and safety would provide more transparency into what these powerful models could do, enabling enterprises to choose models that work best for them.

“We believe this approach supports accountable and transparent evaluation, helping to ensure that each lab’s models continue to be tested against new and challenging scenarios,” OpenAI said in its findings. 

Both companies found that reasoning models, such as OpenAI’s 03 and o4-mini and Claude 4 from Anthropic, resist jailbreaks, while general chat models like GPT-4.1 were susceptible to misuse. Evaluations like this can help enterprises identify the potential risks associated with these models, although it should be noted that GPT-5 is not part ...