{"id":"CVE-2026-11717","state":"PUBLISHED","title":"An authentication bypass vulnerability exists in the generic opaque token validation path (validateOpaqueToken) of googleapis/mcp-toolbox.","description":"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.","publishedAt":"2026-06-18T11:50:23.665Z","updatedAt":"2026-06-18T12:23:15.209Z","severity":{"score":9.3,"label":"Critical","version":"4.0","vector":"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","source":"Google"},"assigner":"Google","products":["Google MCP Toolbox for Databases (googleapis/mcp-toolbox)"],"affected":[{"vendor":"Google","product":"MCP Toolbox for Databases (googleapis/mcp-toolbox)","defaultStatus":"unaffected","versions":[{"version":"1.0.0","status":"affected","lessThanOrEqual":"1.3.0","versionType":"semver"}]}],"references":["https://github.com/googleapis/mcp-toolbox/pull/3341"],"weaknesses":["CWE-287"],"ingestedAt":"2026-10-29T20:10:52.580Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/11xxx/CVE-2026-11717.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-11717","state":"PUBLISHED","datePublished":"2026-06-18T11:50:23.665Z","dateUpdated":"2026-06-18T12:23:15.209Z","assignerShortName":"Google","assignerOrgId":"14ed7db2-1595-443d-9d34-6215bf890778","dateReserved":"2026-06-09T00:41:54.835Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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). 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As a result, Toolbox accepts authorization tokens missing the \"active\" field, granting access to protected tools and underlying data sources."}],"affected":[{"vendor":"Google","product":"MCP Toolbox for Databases (googleapis/mcp-toolbox)","defaultStatus":"unaffected","versions":[{"version":"1.0.0","status":"affected","lessThanOrEqual":"1.3.0","versionType":"semver"}]}],"references":[{"url":"https://github.com/googleapis/mcp-toolbox/pull/3341"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"CRITICAL","baseScore":9.3,"vectorString":"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","lang":"en","description":"CWE-287: Improper Authentication","type":"CWE"}]}],"providerMetadata":{"shortName":"Google","orgId":"14ed7db2-1595-443d-9d34-6215bf890778","dateUpdated":"2026-06-18T11:50:23.665Z"},"impacts":[{"capecId":"CAPEC-114","descriptions":[{"lang":"en","value":"CAPEC-114: Authentication Abuse"}]}],"credits":[{"lang":"en","value":"HaoNH Leader Redteam From VINCSS ( Member Of Vingroup )","type":"finder"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.2"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-18T12:23:05.330652Z","id":"CVE-2026-11717","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-18T12:23:15.209Z"}}]}}}