CVE-2025-71336: Flowise before 3.0.6 (affected versions 2.2.7-patch.1 and earlier) contains an unsandboxed remote code execution vulnerability in the Custom MCP feature, which is designed to execu

criticalCVSS 9.8CVE-2025-71336

Flowise before 3.0.6 (affected versions 2.2.7-patch.1 and earlier) contains an unsandboxed remote code execution vulnerability in the Custom MCP feature, which is designed to execute OS commands such as launching local MCP servers. Because Flowise's authentication and authorization model is minimal and lacks role-based access control, and the default installation runs without authentication unless FLOWISE_USERNAME and FLOWISE_PASSWORD are set, an attacker can send a crafted JSON payload with the header 'x-request-from: internal' to the /api/v1/node-load-method/customMCP endpoint to execute arbitrary OS commands, resulting in complete compromise of the platform container or server.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: critical — CVSS 9.8
Published: 2026-06-25
Last updated: 2026-07-01
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2025-71336

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2025-713360.76% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 51% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2025-71336	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

critical[UPDATE] [critical] Flowise: Multiple vulnerabilitiescert-bund

Recent advisories for Flowise

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

critical[UPDATE] [critical] Flowise: Multiple vulnerabilitiescert-bund · 2026-07-10
high[UPDATE] [high] Flowise: Multiple vulnerabilitiescert-bund · 2026-07-09
mediumCVE-2026-56273: Flowise before 3.1.0 contains a path traversal vulnerability in Faiss and SimpleStore vector s…nvd · 2026-07-08
criticalCVE-2026-56278: Flowise before 3.1.0 (affected versions 3.0.13 and earlier) uses a weak hardcoded default secr…nvd · 2026-06-30
mediumCVE-2026-56277: Flowise before 3.1.2 sets Access-Control-Allow-Origin to a hardcoded wildcard (*) on its text-…nvd · 2026-06-30
mediumCVE-2026-58057: Flowise before 3.1.3 validates Custom MCP stdio environment variables against a denylist using…nvd · 2026-06-28