CVE-2026-40351CWE-943

FastGPT: NoSQL Injection in loginByPassword leads to Authentication Bypass

Critical · published April 17, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
47.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00597 · 47.9th percentile
Weakness
CWE-943 · Improper Neutralization of Special Elements in Data Query Logic
Published
2026-04-17T21:05Z
EPSS history
Timeline
  • 17 APR 21:05Z
    FastGPT: NoSQL Injection in loginByPassword leads to Authentication Bypass
    cvelistv5