RCE in Flowiseai Flowise
CVE-2026-40933
Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.0, due to unsafe serialization of stdio commands in the MCP adapter, an authenticated attacker can add an MCP stdio server with an arbitr…
Vulnerability class: Command Injection (OS Command Injection)
EPSS: 0.001 (22.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Flowiseai Flowise — versions < 3.1.0
- Flowiseai Flowise-components — versions < 3.1.0
Weakness classification (CWE)
References
- https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-c9gw-hvqq-f33r (x_refsource_CONFIRM)
- https://www.ox.security/blog/mcp-supply-chain-advisory-rce-vulnerabilities-across-the-ai-ecosystem (x_refsource_MISC)
- https://www.ox.security/blog/the-mother-of-all-ai-supply-chains-critical-systemic-vulnerability-at-the-core-of-the-mcp (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-40933?
- CVE-2026-40933 is a critical-severity vulnerability in Flowiseai Flowise, classified under OS Command Injection. CVSS score: 10.0/10. Published 2026-04-21.
- How severe is CVE-2026-40933?
- Critical severity. CVSS v3 base score is 10.0 out of 10.