{"items":[{"id":"NVI-00018393","kind":"vulnerability","title":"googleapis/mcp-toolbox: authentication bypass vulnerability in the generic opaque token validation path (validateOpaqueToken)","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-wcpr-6g7x-p44r","CVE-2026-11718"],"plain_summary":"GitHub lists this reviewed advisory for github.com/googleapis/mcp-toolbox. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-1c12d42dc15086430533addddbe3cceb"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-1c12d42dc15086430533addddbe3cceb","url":"https://github.com/advisories/GHSA-wcpr-6g7x-p44r","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-wcpr-6g7x-p44r","publisher":"GitHub Advisory Database","observed_at":"2026-11-06T07:19:16.585Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-1c12d42dc15086430533addddbe3cceb"],"technology":"github.com/googleapis/mcp-toolbox","known_exclusions":[],"conditions_summary":"An authentication bypass vulnerability exists in the generic opaque token validation path (validateOpaqueToken) of googleapis/mcp-toolbox.\n\nWhen 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.","public_affected_ranges":["< 1.4.0"]}],"null_published_at":"2026-11-07T07:07:39.831Z","source_updated_at":"2026-06-19T16:59:28.000Z","source_disclosed_at":"2026-06-18T15:32:01.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-06T07:19:16.585Z"}],"next_cursor":null,"snapshot_revision":"42594"}