# CVE-2025-8943: Unsupervised OS command execution leads to remote code execution by unauthenticated network attackers

> Unauthenticated attackers can execute arbitrary OS commands via the Custom MCPs feature in Flowise, leading to remote code execution.

- **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:** 14 Aug 2025
- **Updated:** 18 Aug 2025
- **Also known as:** GHSA-2vv2-3x8x-4gv7

## What is CVE-2025-8943?

CVE-2025-8943 is a critical command injection vulnerability in Flowiseai Flowise, published on 14 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Custom MCPs feature is designed to execute OS commands, for instance, using tools like `npx` to spin up local MCP Servers. However, Flowise's inherent authentication and authorization model is minimal and lacks role-based access controls (RBAC). Furthermore, in Flowise versions before 3.0.1 the default installation operates without authentication unless explicitly configured. This combination allows unauthenticated network attackers to execute unsandboxed OS commands.

Weakness: CWE-862 (Missing Authorization), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2025-8943?

2 open source packages ship an affected version, including flowise. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `flowise` | npm | All versions to 3.0.5 | None |
| `flowise` | npm | All versions to 3.0.5 | None |

Products: Flowiseai Flowise.

## How do I fix CVE-2025-8943?

No fix has been published for CVE-2025-8943 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-8943 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-8943 exists.

Public exploit code:

- Flowise Custom MCP Remote Code Execution (metasploit)
- Flowise < 3.0.1 - Remote Command Execution (nuclei): http/cves/2025/CVE-2025-8943.yaml

## Other vulnerabilities in Flowiseai Flowise

- [CVE-2025-71338](https://insights.sbomify.com/CVE-2025-71338/): Flowise through 2.2.7 - Arbitrary File Write to Remote Code Execution via document-store API (critical 10.0)
- [CVE-2026-40933](https://insights.sbomify.com/CVE-2026-40933/): Flowise: Authenticated RCE Via MCP Adapters (critical 10.0)
- [CVE-2025-61913](https://insights.sbomify.com/CVE-2025-61913/): Flowise is vulnerable to arbitrary file read, arbitrary file write (critical 10.0)
- [CVE-2025-59528](https://insights.sbomify.com/CVE-2025-59528/): Flowise has Remote Code Execution vulnerability (critical 10.0)
- [CVE-2026-52098](https://insights.sbomify.com/CVE-2026-52098/): Code injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-8943 and fix it if it is affected.

What it is: CVE-2025-8943 is a critical command injection vulnerability in Flowiseai Flowise, published on 14 Aug 2025. 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-2025-8943 exists.

Affected packages and fixed versions:
- flowise (npm): affected all versions up to 3.0.5; no fix listed
- flowise (npm): affected all versions up to 3.0.5; no fix listed

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-2025-8943/ (Markdown: https://insights.sbomify.com/CVE-2025-8943/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-8943
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-8943
- OSV: https://osv.dev/vulnerability/CVE-2025-8943

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-8943/
Summaries are generated and may contain mistakes; the official description above is the record.