Fireworks AI breach exposed Notion AI chat transcripts

Fireworks says it has tens of thousands of customers worldwide, including legal tech company Harvey and AI company Cursor. Notion is at least one confirmed victim, and it says the breach touched around 1% of its own customers.

What data did the Fireworks AI breach expose at Notion?

Notion says Fireworks warned it about a security incident and later confirmed that Notion customer data had been stolen. On November 3, Notion disconnected its systems from Fireworks, deleted the data stored there and cut all connectivity between the two.

This week Notion confirmed that the hackers took chat transcripts from Notion AI customers who used the Insights feature. Those transcripts include "any input to or output from the model that was written to the chat." Notion added that much of the data was unattributable, so it cannot tell which customer it came from.

Why would hackers want this?

Fireworks believes the attackers are financially motivated. Their aim, it says, is to sell tokens, meaning access to large language models. Buyers can then burn through AI model usage without paying for the computing themselves.

This is the second breach to hit Fireworks in as many months, after a security incident in October. It also shows how one company's AI features often run on another company's infrastructure, so a single break-in can spill over to every customer downstream.