{"id":82773,"date":"2026-07-31T06:46:24","date_gmt":"2026-07-31T03:16:24","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2026-14541-authentication-bypass-and-audience-confusion-in-mcp-toolbox-oauth-provider\/"},"modified":"2026-07-31T06:46:24","modified_gmt":"2026-07-31T03:16:24","slug":"cve-2026-14541-authentication-bypass-and-audience-confusion-in-mcp-toolbox-oauth-provider","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2026-14541-authentication-bypass-and-audience-confusion-in-mcp-toolbox-oauth-provider\/","title":{"rendered":"CVE-2026-14541 &#8211; Authentication Bypass and Audience Confusion in MCP Toolbox OAuth Provider"},"content":{"rendered":"<p>CVE ID :CVE-2026-14541<\/p>\n<p>  Published : July 31, 2026, 3:16 a.m. | 29\u00a0minutes ago<\/p>\n<p>  Description :An authentication bypass and audience confusion vulnerability exists in the Google OAuth provider component of Google mcp-toolbox version 1.4.0. When a Google authService is initialized with mcpEnabled: true but lacks an explicitly defined audience or clientId, the ValidateMCPAuth pipeline for opaque tokens skips audience validation entirely. As a result, the toolbox will accept any valid Google OAuth access token\u2014even those minted for unrelated ecosystem applications\u2014granting unauthorized clients access to protected tools and data backends.<\/p>\n<p>  Severity: 8.0 | HIGH<\/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-2026-14541 Published : July 31, 2026, 3:16 a.m. | 29\u00a0minutes ago Description :An authentication bypass and audience confusion vulnerability exists in the Google OAuth provider component of Google mcp-toolbox version 1.4.0. When a Google authService is initialized with mcpEnabled: true but lacks an explicitly defined audience or clientId, the ValidateMCPAuth pipeline for opaque &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-82773","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/82773","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=82773"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/82773\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=82773"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=82773"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=82773"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}