CVE-2026-40351: Fastgpt

Critical severity, CVSS 9.8. EPSS: 0.6% chance of exploitation in the next 30 days.

FastGPT is an AI Agent building platform. In versions prior to 4.14.9.5, the password-based login endpoint uses TypeScript type assertion without runtime validation, allowing an unauthenticated attacker to pass a MongoDB query operator object (e.g., {"$ne": ""}) as the password field. This NoSQL injection bypasses the password check, enabling login as any user including the root administrator. This issue has been fixed in version 4.14.9.5.

Affected products

• Fastgpt Fastgpt: before 4.14.9.5 (fixed in 4.14.9.5)

Published 2026-04-17. Last modified 2026-06-17.