TREK MCP trip summary bypasses delegated OAuth read scopes
Collected exploitation and prediction evidence
Risk source coverageCISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.
No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.
cve-program · CVE-2026-77321
PublishedTREK is a collaborative travel planner. Prior to 3.3.0, the get_trip_summary tool in server/src/mcp/tools/trips.ts is registered for scoped OAuth MCP tokens without requiring trips:read and returns core trip summary data regardless of the delegated scopes. A token granted only an unrelated capability, such as weather:read, can receive trip metadata, member email addresses from server/src/services/tripService.ts, itinerary days, and accommodations for every trip accessible to the token's user. Cross-user trip authorization remains enforced, but the missing scope check defeats the consented least-privilege boundary and exposes trip content and third-party contact information to an MCP client that was not authorized to read it. This issue is fixed in version 3.3.0.
- Source published
- 24 Sep 2026 18:04:05 UTC
- Source modified
- 5 Oct 2026 15:32:36 UTC
- Observed here
- 23 Oct 2026 15:48:27 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
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CVSS 3.1 · 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N