{"id":"CVE-2026-11717","details":"An authentication bypass vulnerability exists in the generic opaque token validation path (validateOpaqueToken) of googleapis/mcp-toolbox.\n\nWhen verifying an unparsed opaque token via an OAuth 2.0 introspection endpoint (RFC 7662), the toolbox decodes the response into an introspectResp struct where the Active field is declared as a pointer to a boolean (*bool). The code only explicitly rejects a token if the response contains a populated active field set to false (if introspectResp.Active != nil && !*introspectResp.Active). If an introspection endpoint responds with a payload that completely omits the mandatory active key, the internal variable remains nil, causing the conditional check to short-circuit. As a result, Toolbox accepts authorization tokens missing the \"active\" field, granting access to protected tools and underlying data sources.","aliases":["GHSA-8fcc-w5hv-4gxv","GO-2026-5251"],"modified":"2026-07-08T08:12:39.869675122Z","published":"2026-06-18T11:50:23.665Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/11xxx/CVE-2026-11717.json","cwe_ids":["CWE-287"],"cna_assigner":"Google"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/11xxx/CVE-2026-11717.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-11717"},{"type":"FIX","url":"https://github.com/googleapis/mcp-toolbox/pull/3341"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/googleapis/mcp-toolbox","events":[{"introduced":"8b07b2d3be308cca1b878929dc96a6d54004cafd"},{"last_affected":"b0010060a939455d91e4f8ba62dc3e72b1892469"}],"database_specific":{"extracted_events":[{"introduced":"1.0.0"},{"last_affected":"1.3.0"}],"source":"AFFECTED_FIELD"}}],"versions":["v1.3.0","v1.2.0","v1.1.0","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-11717.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"}]}