CVE-2026-56274 Details
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.
A vulnerability allowing OS command injection has been identified in Flowise versions prior to 3.1.2. This issue arises in the Custom MCP Server feature, where incomplete validation of command flags and a regex bypass in local file access restrictions create exploitable conditions. An attacker with a Flowise account of any role, or API access with view/update permissions for chatflows, can manipulate a malicious MCP server to circumvent the validateCommandFlags blocklist and the validateArgsForLocalFileAccess checks. This exploitation leads to the execution of arbitrary commands on the Flowise host.
Users are advised to update Flowise to version 3.1.2 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 23, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q | CISA-ADP | ExploitThird Party Advisory |
| https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q | [email protected] | ExploitThird Party Advisory |
| https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess | [email protected] | Third Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-78 | Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| flowiseai flowise | < 3.1.2 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 25, 2026 | Initial Analysis | [email protected] |
| Jun 24, 2026 | CVE Modified | [email protected] |
| Jun 23, 2026 | CVE Modified | CISA-ADP |
| Jun 23, 2026 | New CVE Received | [email protected] |