fix authz-vuln-04

[0xcucumbersalad]

Fix: Authorization Vulnerability in OAuth Proxy Endpoint

What is this contribution about?

Endpoint: ALL /oauth-proxy/:connectionId/*

This PR fixes a critical authorization vulnerability where unauthenticated attackers could hijack OAuth authorization flows for any connection across organizations.

The issue allowed malicious actors to initiate or manipulate OAuth flows without proper authentication or ownership validation of the connectionId.

This update ensures:

• Proper authentication is enforced
• Authorization checks validate ownership of the connection
• Cross-organization OAuth hijacking is no longer possible

---

Summary by cubic

Enforce authentication and organization ownership checks on all /oauth-proxy/:connectionId/* endpoints to block cross‑org OAuth hijacking. Adds E2E coverage for 401, 403, and 404 behaviors across authorize, token, and register flows.

• Bug Fixes
  • Return 401 for unauthenticated requests (no user session or API key) before connection lookup in apps/mesh/src/api/app.ts.
  • Return 404 for non-existent connections.
  • Return 403 when the connection’s organization_id differs from the current organization across authorize, token, and register endpoints.

^{Written for commit e88cda5. Summary will update on new commits.}

[github-actions]

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[github-actions]

Release Options

Should a new version be published when this PR is merged?

React with an emoji to vote on the release type:

Reaction	Type	Next Version
👍	Prerelease	2.113.2-alpha.1
🎉	Patch	2.113.2
❤️	Minor	2.114.0
🚀	Major	3.0.0

Current version: 2.113.1

Deployment

• Deploy to production (triggers ArgoCD sync after Docker image is published)

[cubic-dev-ai]

No issues found across 1 file

[viktormarinho]

@0xcucumbersalad plz fix checks and also check if this also handles IDOR for users that are logged in but hijacking another org's mcps?