# CVE-2026-40252: Broken Access Control (IDOR) Leading to Cross-Tenant Application Access in FastGPT

> Authenticated users can access and execute other teams' private AI applications by manipulating application IDs, leading to cross-tenant data exposure.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Apr 2026
- **Updated:** 13 Apr 2026
- **Also known as:** GHSA-gc8m-w37w-24hw

## What is CVE-2026-40252?

CVE-2026-40252 is a medium-severity missing authorization vulnerability in labring FastGPT, published on 10 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

FastGPT is an AI Agent building platform. Prior to 4.14.10.4, Broken Access Control vulnerability (IDOR/BOLA) allows any authenticated team to access and execute applications belonging to other teams by supplying a foreign appId. While the API correctly validates the team token, it does not verify that the requested application belongs to the authenticated team. This leads to cross-tenant data exposure and unauthorized execution of private AI workflows. This vulnerability is fixed in 4.14.10.4.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key), CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-40252?

It affects 1 product.


Products: Fastgpt Fastgpt.

## How do I fix CVE-2026-40252?

No fix has been published for CVE-2026-40252 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-40252 being exploited?

There is no known exploitation of CVE-2026-40252 in the wild and no public exploit code.

## 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-2026-40351](https://insights.sbomify.com/CVE-2026-40351/): FastGPT: NoSQL Injection in loginByPassword leads to Authentication Bypass (critical 9.8)
- [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)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40252 and fix it if it is affected.

What it is: CVE-2026-40252 is a medium-severity missing authorization vulnerability in labring FastGPT, published on 10 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-40252 in the wild and no public exploit code.

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-2026-40252/ (Markdown: https://insights.sbomify.com/CVE-2026-40252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40252
- OSV: https://osv.dev/vulnerability/CVE-2026-40252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40252/
Summaries are generated and may contain mistakes; the official description above is the record.