CVE-2026-56274 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-56274HIGH

Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   N   L   N   H   H   H    8.7   .0327   87.4     —

AFFECTED
  Product             Versions     Fixed
  Flowise             unspecified  3.1.2
  Flowise Components  unspecified  3.1.2

TIMELINE
  Jun 20  Reserved by VulnCheck
  Jun 23  EXPLOIT PUBLISHED — CVE-2026-56274 (Flowise). Public exploit reference added.
  Jun 23  Published (CNA: VulnCheck)

CWE-78 · CNA: VulnCheck · CVSS v4.0 · 2 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
June 20, 2026	Reserved	Reserved by VulnCheck
June 23, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-56274 (Flowise). Public exploit reference added.
June 23, 2026	Published	Published (CNA: VulnCheck)

Affected

Affected products and packages — 2 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Flowise	Flowise	—	—	3.1.2
Flowise	Flowise Components	—	—	3.1.2

Weaknesses

CWE-78

References (2)

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]

Authoritative record: CVE-2026-56274 at cve.org

Vendors: flowise

Weaknesses: CWE-78

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-56274 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.