Fireworks AI: second breach via third-party cloud provider exposes customer billing data and model assets
Severity: high · Patch status: no-fix-needed · Since 2026-11-09
On 2026-10-23 a third-party cloud provider that hosted Fireworks' R&D machines had a security incident. On 2026-10-24 the attacker used that access to reach Fireworks development machines and run an unauthorized workload, which Fireworks says caused further customer data impact. Fireworks detected the activity the same day, revoked and replaced credentials and service accounts, restricted network paths, isolated affected systems and tightened storage access, and reports no further unauthorized access on the customer-facing platform as of 2026-10-25. The exposed internal application gave access to resource metadata and billing data (addresses, invoices, payment history, balances and credit usage). Payment card numbers are not stored and were not affected. For a limited set of accounts, secrets, datasets and incomplete model weights were also accessed. Fireworks says inference, Training SDK and Nexus show no impact (all zero data retention by default). The cloud provider is not named. Fireworks says the evidence links the wider incident to LLMjacking actors, and that Unit 42 is helping with forensics. This is a second incident, separate from the early-October eval-job credential exposure.
What to do
- If Fireworks notified your account, follow that notice; if it did not, Fireworks says no incident-specific action is currently required
- Review billing, invoices and account activity for anything you do not recognise, and send unrecognised users, evaluators, training jobs, datasets or key IDs to security@fireworks.ai
- If your account is named in a notice, assume any datasets or model artifacts stored in Fireworks may have been taken and assess the IP and data exposure
- Rotate any third-party credentials that were stored as Fireworks secrets, including any named in the early-October notice; removing a stored secret does not revoke the credential
- Enforce least-privilege access and network segmentation on cloud-hosted development environments
Sources
All live incidents on Threat Watch
