# CVE-2026-73601: Flowise before 3.1.3 Remote Code Execution via Custom MCP

> Authenticated attackers can execute arbitrary system commands in Flowise by manipulating environment variables in the Custom MCP node when stdio protocol is enabled.

- **Severity:** Critical 9.0 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **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:** 13 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-g98q-rm45-q9h8, GHSA-m2vg-4724-xj8g

## What is CVE-2026-73601?

CVE-2026-73601 is a critical command injection vulnerability in Flowiseai Flowise, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Flowise versions before 3.1.3 contain a remote code execution vulnerability in the Custom MCP node when CUSTOM_MCP_PROTOCOL is set to stdio, allowing authenticated users to execute arbitrary commands by manipulating environment variables and command arguments. Attackers can abuse PYTHONWARNINGS and BROWSER environment variables with python3, or leverage the root working directory with node to bypass validation and execute system commands.

Weakness: CWE-95 (Improper Neutralization of Directives in Dynamically Evaluated Code)

## Which versions are affected by CVE-2026-73601?

It affects 1 product.


Products: Flowiseai Flowise.

## How do I fix CVE-2026-73601?

No fix has been published for CVE-2026-73601 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-73601 being exploited?

There is no known exploitation of CVE-2026-73601 in the wild and no public exploit code.

## 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-2026-73601 and fix it if it is affected.

What it is: CVE-2026-73601 is a critical command injection vulnerability in Flowiseai Flowise, published on 13 Aug 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-2026-73601 in the wild and no public exploit code.

Affected product: Flowiseai Flowise. 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-2026-73601/ (Markdown: https://insights.sbomify.com/CVE-2026-73601/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73601
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73601
- OSV: https://osv.dev/vulnerability/CVE-2026-73601

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73601/
Summaries are generated and may contain mistakes; the official description above is the record.