Mistral AI Releases Leanstral 1.5 Solving 587 Putnam Problems and Announces Open-Weight Model Early Access in July 2026

On July 7, 2026, Mistral AI announced the upcoming release of its open-weight large language model, which will be available for early access in July. The model aims to address the AI frontier gap by providing cutting-edge capabilities.

On July 6, 2026, Mistral released Leanstral 1.5, an open-source large language model that notably solved 587 of 672 problems from the challenging Putnam math competition. This achievement highlights the model's advanced mathematical reasoning capabilities.

Mistral revealed its open-model variant, Leanstral 1.5, on July 6, 2026, which successfully solved 587 out of 672 Putnam math problems. This release underscores significant progress in AI-driven mathematical problem solving.

Mistral AI reiterated on July 7, 2026, that its open-weight large language model would enter early access in July, emphasizing its mission to close the AI capability frontier gap with this new model.