CVE-2026-56274 Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess
Attackers can execute arbitrary commands on the host by configuring a malicious MCP server that bypasses validation checks in Flowise.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-56274?
CVE-2026-56274 is a high-severity command injection vulnerability in Flowiseai Flowise, published on 23 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature due to incomplete command-flag validation and a regex bypass in local file access restrictions. An attacker with a Flowise account of any role, or API access with view/update permissions for chatflows, can configure a malicious MCP server to bypass the validateCommandFlags blocklist (for example, 'docker build' is not blocked, and 'npx --yes' is not blocked while only '-y' is) and the validateArgsForLocalFileAccess checks, resulting in execution of arbitrary commands on the Flowise host.
Weakness: CWE-78
Which versions are affected by CVE-2026-56274?
4 open source packages ship an affected version, including flowise and flowise-components. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
flowise npm | All versions | 3.1.2 |
flowise npm | All versions | 3.1.2 |
flowise-components npm | All versions | 3.1.2 |
flowise-components npm | All versions | 3.1.2 |
Products include Flowiseai Flowise.
How do I fix CVE-2026-56274?
Upgrade flowise to 3.1.2 or later.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-56274 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56274 exists.
Public exploit code: 1 Metasploit module.
Other vulnerabilities in Flowiseai Flowise
- CVE-2025-71338 Flowise through 2.2.7 - Arbitrary File Write to Remote Code Execution via document-store API
- CVE-2026-40933 Flowise: Authenticated RCE Via MCP Adapters
- CVE-2025-61913 Flowise is vulnerable to arbitrary file read, arbitrary file write
- CVE-2025-59528 Flowise has Remote Code Execution vulnerability
- CVE-2026-52098 Code injection in n/a
Sources
Also known as GHSA-8rhx-2hcv-q49g, GHSA-m99r-2hxc-cp3q.