Fireworks AI hack leaks Notion chat transcripts after cloud breach

> Fireworks AI says its cloud provider was breached, opening a door into a development system — and some customer data walked out with the intruders.

The company confirmed the attack in a security advisory, saying the cybercriminals grabbed billing information and some datasets. Fireworks pitches its platform to tens of thousands of customers worldwide, a roster that includes legal tech firm Harvey and AI company Cursor — names that make the spillover risk concrete.

Notion is the confirmed casualty so far. The document and notetaking company said the breach touched roughly 1% of its customers. After Fireworks flagged the incident, Notion says it cut its systems loose from Fireworks on November 3, wiped the data stored in its own systems, and shut down all connectivity between the two.

This week Notion confirmed what the hackers actually took: chat transcripts belonging to Notion AI users who tapped the “Insights” feature. According to Notion, those transcripts capture any input to or output from the model that was written into the chat. The company added that much of the data was unattributable, meaning it couldn't tell which customer it came from.

Fireworks believes the attackers were in it for money, targeting token sales from breached access to large language models. That playbook sells entry to unauthorized third parties who then burn through AI model usage without spending their own resources. It's the second breach to hit Fireworks in as many months, after a security incident in October — and a reminder of how one provider's bad day becomes another company's data loss.