CVE-2026-56274
Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess
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.
INFO
Published Date :
June 23, 2026, 1:16 p.m.
Last Modified :
June 25, 2026, 6:39 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Flowise to version 3.1.2 or later.
- Validate MCP server configurations for malicious inputs.
- Review and restrict user permissions for chatflow management.
Public PoC/Exploit Available at Github
CVE-2026-56274 has a 3 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-56274.
| URL | Resource |
|---|---|
| https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q | Exploit Third Party Advisory |
| https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess | Third Party Advisory |
| https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q | Exploit Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56274 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-56274
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Profile README
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Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-56274 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56274 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 25, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:* versions up to (excluding) 3.1.2 Added Reference Type VulnCheck: https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q Types: Exploit, Third Party Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess Types: Third Party Advisory Added Reference Type CISA-ADP: https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q Types: Exploit, Third Party Advisory -
CVE Modified by [email protected]
Jun. 24, 2026
Action Type Old Value New Value Changed Affected [{'vendor': 'Flowise', 'product': 'Flowise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.2', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise', 'defaultStatus': 'unaffected'}, {'vendor': 'Flowise', 'product': 'Flowise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.2', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise-components', 'defaultStatus': 'unaffected'}] [{'vendor': 'Flowise', 'product': 'Flowise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.2', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise', 'defaultStatus': 'unaffected'}, {'vendor': 'Flowise', 'product': 'Flowise Components', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.2', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise-components', 'defaultStatus': 'unaffected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 23, 2026
Action Type Old Value New Value Added Reference https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q Added SSVC {'id': 'CVE-2026-56274', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-23T13:05:16.597724Z'} -
New CVE Received by [email protected]
Jun. 23, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Flowise', 'product': 'Flowise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.2', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise', 'defaultStatus': 'unaffected'}, {'vendor': 'Flowise', 'product': 'Flowise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.1.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.1.2', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/flowise-components', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Added CWE CWE-78 Added Reference https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q Added Reference https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess