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

> Unauthenticated attackers can bypass password checks via NoSQL injection to log in as any user, including administrators, in FastGPT.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Apr 2026
- **Updated:** 20 Apr 2026
- **Also known as:** GHSA-x8mx-2mr7-h9xg

## 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 (Improper Neutralization of Special Elements in Data Query Logic)

## Which versions are affected by CVE-2026-40351?

It affects 1 product.


Products: 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.

## 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](https://insights.sbomify.com/CVE-2026-34162/): FastGPT: Unauthenticated SSRF via httpTools Endpoint Leads to Internal API Key Theft (critical 10.0)
- [CVE-2026-33075](https://insights.sbomify.com/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](https://insights.sbomify.com/CVE-2026-40352/): FastGPT: NoSQL Injection in updatePasswordByOld Leads to Account Takeover (high 8.8)
- [CVE-2026-34163](https://insights.sbomify.com/CVE-2026-34163/): Server-Side Request Forgery via MCP Tools Endpoint in FastGPT (high 7.7)
- [CVE-2026-26075](https://insights.sbomify.com/CVE-2026-26075/): Cross-Site Request Forgery (CSRF) in FastGPT (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40351 and fix it if it is affected.

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

Affected product: labring FastGPT. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-40351/ (Markdown: https://insights.sbomify.com/CVE-2026-40351/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40351
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40351
- OSV: https://osv.dev/vulnerability/CVE-2026-40351

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40351/
Summaries are generated and may contain mistakes; the official description above is the record.