An authentication bypass vulnerability exists in the generic opaque token validation path (validateOpaqueToken) of googleapis/mcp-toolbox.
Exact source revision recorded 25 Oct 2026 05:17:25 UTC. It does not establish the source's current position. Latest evidence.
nvd · CVE-2026-11717
PublishedAn authentication bypass vulnerability exists in the generic opaque token validation path (validateOpaqueToken) of googleapis/mcp-toolbox. When 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.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-287
Original publisher date fields
published: 2026-06-18T14:17:20.013
lastModified: 2026-08-17T16:13:01.247
1 source CPE criteria · context only
- cpe:2.3:a:google:mcp_toolbox_for_databases:*:*:*:*:*:*:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 18 Jun 2026 14:17:20 UTC
- Source modified
- 17 Aug 2026 16:13:01 UTC
- Observed here
- 25 Oct 2026 05:17:25 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.
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