{"id":"CVE-2026-58057","title":"Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity","summary":"Flowise before 3.1.3 validates Custom MCP stdio environment variables against a denylist using a case-sensitive comparison, so on Windows, where environment names are case-insensitive, supplying 'node_options' bypasses the NODE_OPTIONS d…","severity":"medium","cvss":5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L","cvssSource":"cna","cwe":["CWE-178"],"vendor":"Flowise","product":"Flowise","affected":["Flowise < 3.1.3"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-06-29T12:23:43.023783Z"},"exploitAvailable":true,"published":"2026-06-28","updated":"2026-11-08","sourceUpdated":"2026-11-08T14:06:43.889Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-58057","references":[{"url":"https://github.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-poc","label":"Proof of Concept"},{"url":"https://github.com/FlowiseAI/Flowise/pull/6471","label":"Fix (PR #6471, 3.1.3)"},{"url":"https://www.vulncheck.com/advisories/flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity","label":"VulnCheck Advisory: Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity"}],"tags":["cve.org","exploit-available"],"epss":0.01556,"epssPercentile":0.75351,"exploits":{"exploitdb":true,"github":1,"githubRepos":["https://github.com/CerberusMrXi/Flowise-CVE-2026-58057-exploit"],"checkedAt":"2026-11-08T14:51:57.334Z"},"ingestedAt":"2026-11-08T14:51:22.311Z","slug":"CVE-2026-58057","body":"## Overview\n\nFlowise before 3.1.3 validates Custom MCP stdio environment variables against a denylist using a case-sensitive comparison, so on Windows, where environment names are case-insensitive, supplying 'node_options' bypasses the NODE_OPTIONS denylist entry. An authenticated user who can configure a Custom MCP node can thereby inject NODE_OPTIONS --require and execute arbitrary code in the Flowise server context.\n\n## Affected\n\n- `Flowise < 3.1.3`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":27.5,"likelihood":0.3,"exploitation":12,"ransomware":0},"changes":[]}