criticalCVSS 9.9NVD status: Analyzed

CVE-2026-56274

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.

ComponentFlowise
Severitycritical (CVSS 9.9)
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Published (NVD)2026-06-23
Last modified2026-06-25
Affected versions
flowise < 3.1.2
Fixed in3.1.2
WeaknessCWE-78
CISA KEVnot listed

NVD 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.

Does CVE-2026-56274 hit the version you run?Paste your docker-compose.yml, requirements.txt or package.json. The scanner checks your pinned versions against this CVE and every other one we track for Flowise.
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What to do

  • Upgrade Flowise to 3.1.2 or later.
  • Do not expose the component's API or UI to the internet without authentication in front of it.

Sources

Other Flowise CVEs

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