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CVE-2026-56274

CRITICAL Exploitation: PoC
9.9
CVSS 3.1
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.

Metadata

CVE ID
CVE-2026-56274
State
PUBLISHED
Assigner
VulnCheck
Reserved
2026-06-20 01:47 UTC
Published
2026-06-23 12:13 UTC
Last updated
2026-06-23 13:05 UTC
Primary CWE
CWE-78
Improper Neutralization of Special Elements used in an OS Co…
Vendor / Product
Flowise / Flowise
Sources
cve.org  ·  NVD

Severity & Metrics

9.9 CRITICAL CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
SSVC — CISA Coordinator
Exploitation
PoC
Automatable
no
Tech. Impact
total
Affected products (2)
VendorProductPlatformVersions
Flowise Flowise — 0 < 3.1.2, 3.1.2
Flowise Flowise — 0 < 3.1.2, 3.1.2
Weakness (CWE)
CWESourceDescription
CWE-78 cna Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CVSS scores (2)
ScoreSeverityVersionSourceVector
9.9 CRITICAL 3.1 cna CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
8.7 HIGH 4.0 cna CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References (2)
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