CVE-2026-40351 FastGPT: NoSQL Injection in loginByPassword leads to Authentication Bypass

What is CVE-2026-40351?

CVE-2026-40351 is a critical authentication bypass vulnerability in labring FastGPT, published on 17 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-943

Which versions are affected by CVE-2026-40351?

It affects 1 product.

Products include Fastgpt Fastgpt.

How do I fix CVE-2026-40351?

No fix has been published for CVE-2026-40351 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-40351 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40351 exists.

Other vulnerabilities in labring FastGPT

• CVE-2026-34162 FastGPT: Unauthenticated SSRF via httpTools Endpoint Leads to Internal API Key Theft Critical 10.0
• CVE-2026-33075 FastGPT has Arbitrary Code Execution in GitHub Actions via pull_request_target in fastgpt-preview-image.yml Critical 9.4
• CVE-2026-40352 FastGPT: NoSQL Injection in updatePasswordByOld Leads to Account Takeover High 8.8
• CVE-2026-34163 Server-Side Request Forgery via MCP Tools Endpoint in FastGPT High 7.7
• CVE-2026-26075 Cross-Site Request Forgery (CSRF) in FastGPT Medium 6.9

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-x8mx-2mr7-h9xg.