{"id":"CVE-2026-91931","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-91931","generatedAt":"2026-09-20T15:04:29.711Z","title":"Flowise before 3.1.4 contains a remote code execution vulnerability in the Custom MCP node that allows authenticated attackers to execute arbitrary code by supplying npx package names in the mcpServerConfig parameter.","description":"Flowise before 3.1.4 contains a remote code execution vulnerability in the Custom MCP node that allows authenticated attackers to execute arbitrary code by supplying npx package names in the mcpServerConfig parameter. Attackers can invoke npx with attacker-controlled npm packages to execute code on the Flowise server.","published":"2026-09-15T16:17:44.000Z","lastModified":"2026-09-17T15:16:57.000Z","status":"Received","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":9,"severity":"CRITICAL","vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-78"],"affected":[],"epss":{"score":0.00629,"percentile":0.48753,"date":"2026-09-19","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.63%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-vcwp-f9rq-3887","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/flowise-before-3.1.4-remote-code-execution-via-custom-mcp-npx","source":"disclosure@vulncheck.com"},{"url":"https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-vcwp-f9rq-3887","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-91931","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}