CVE-2026-11718: Google MCP Toolbox for Databases (googleapis/mcp-toolbox) vulnerability
Google · MCP Toolbox for Databases (googleapis/mcp-toolbox)
Affected: Google MCP Toolbox for Databases (googleapis/mcp-toolbox) · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 8% of scored CVEs
DescriptionCVE.org
An authentication bypass vulnerability exists in the generic opaque token validation path (validateOpaqueToken) of googleapis/mcp-toolbox. When the toolbox validates an opaque token via an OAuth 2.0 introspection endpoint (RFC 7662), it decodes the response into an introspectResp struct. However, the subsequent claim-checking logic (validateClaims) evaluates the issuer condition as if a.issuer != "" && iss != "". If the external OAuth provider's introspection response omits the optional iss (issuer) field completely, the variable iss defaults to an empty string. This causes the conditional block to evaluate to false and be skipped silently. Consequently, the application accepts tokens issued by unauthorized or unintended third-party identity providers.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Google · MCP Toolbox for Databases (googleapis/mcp-toolbox)from 1.0.0 up to and including 1.3.0
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CoverageNo articles yet
No CyberSIXT article names CVE-2026-11718 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.