{"id":81166,"date":"2026-06-28T05:02:58","date_gmt":"2026-06-28T01:32:58","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2026-58057-flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity\/"},"modified":"2026-06-28T05:02:58","modified_gmt":"2026-06-28T01:32:58","slug":"cve-2026-58057-flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2026-58057-flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity\/","title":{"rendered":"CVE-2026-58057 &#8211; Flowise &#8211; Custom MCP Environment Variable Denylist Bypass via Case Sensitivity"},"content":{"rendered":"<p>CVE ID :CVE-2026-58057<\/p>\n<p>  Published : June 28, 2026, 1:32 a.m. | 2\u00a0hours, 12\u00a0minutes ago<\/p>\n<p>  Description :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 &#8216;node_options&#8217; bypasses the NODE_OPTIONS denylist entry. An authenticated user who can configure a Custom MCP node can thereby inject NODE_OPTIONS &#8211;require and execute arbitrary code in the Flowise server context.<\/p>\n<p>  Severity: 5.0 | MEDIUM<\/p>\n<p>  Visit the link for more details, such as CVSS details, affected products, timeline, and more&#8230;\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>CVE ID :CVE-2026-58057 Published : June 28, 2026, 1:32 a.m. | 2\u00a0hours, 12\u00a0minutes ago Description :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 &#8216;node_options&#8217; bypasses the NODE_OPTIONS denylist entry. An authenticated user who can configure a Custom MCP &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-81166","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/81166","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=81166"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/81166\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=81166"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=81166"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=81166"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}