Fireworks has disclosed that a third-party cloud service provider hosting its R&D machines experienced a security incident on October 23. The following day, the attacker leveraged this compromise to intrude into Fireworks' development machines and run unauthorized tasks, resulting in some customer account and billing information being affected. A small number of accounts also had their keys, datasets, and unfinished model weights impacted. The affected information includes billing addresses, invoices, and payment records; Fireworks does not store payment card numbers, and card numbers were not affected. Since October 25, no further successful access by the attacker to the customer-facing platform has been detected. The company is currently working with professional teams to conduct an investigation and has temporarily disabled self-service dataset upload and download functions used for batch inference and dataset-based training.