# CVE-2026-100307: Amazon mcp-gateway-registry authorization bypass in management API

Source: https://junglewise.ai/threats/cve-2026-100307-missing-authorization-on-the-external-management-api-in-mcp  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-11. Updated: 2026-11-11  
License: CC BY 4.0 with a link back

CVE-2026-100307 · Severity: high · CVSS 8.8 · Published 2026-11-11

Amazon mcp-gateway-registry is a registry and gateway for Model Context Protocol servers that manages discovery and access control for gateway assets. An authenticated user without administrative privileges can exploit a missing authorization check in the management API to grant themselves registry administrator access, gaining full control over all registered gateway assets and the ability to read stored credentials.

Technologies: [Amazon AWS](https://junglewise.ai/threats/technologies/aws), [Amazon Mcp-Gateway-Registry](https://junglewise.ai/threats/technologies/mcp-gateway-registry). Vendors: [Amazon](https://junglewise.ai/threats/vendors/amazon).

## Quick answers

**Is CVE-2026-100307 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-100307 being exploited in the wild.

**How severe is CVE-2026-100307?** High severity, with a CVSS score of 8.8, published 11 November 2026.

**Which products and versions are affected?** Amazon Mcp-Gateway-Registry 1.0.9 through 1.24.7.

**Is there a fix for CVE-2026-100307?** Yes: fixed in 1.25.0. Until then: Restrict access to POST /api/servers/groups/* and related /api/servers/* mutation routes at the ingress layer to trusted administrator identities only. Monitor the mcp_scopes DocumentDB collection for unexpected changes to group_mappings and ui_permissions. Review application HTTP logs for POST /api/servers/groups/import requests from non-administrator accounts. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-100307 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-100307?** Check whether you run Amazon AWS or Amazon Mcp-Gateway-Registry at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.25.0

Restrict access to POST /api/servers/groups/* and related /api/servers/* mutation routes at the ingress layer to trusted administrator identities only. Monitor the mcp_scopes DocumentDB collection for unexpected changes to group_mappings and ui_permissions. Review application HTTP logs for POST /api/servers/groups/import requests from non-administrator accounts.

## Technical details

The external management API endpoints (/api/servers/*) perform authentication but lack role-based authorization checks. A low-privileged authenticated user can submit a crafted group import request to POST /api/servers/groups/import that maps their identity provider group to the mcp-registry-admin scope, achieving privilege escalation without re-authentication. The vulnerability affects versions 1.0.9 through 1.24.7 and is fixed in version 1.25.0.

## Affected products

- Amazon mcp-gateway-registry 1.0.9 through 1.24.7

## Timeline

- 2026-11-11: disclosed
- 2026-06-27: patched

## References

- [https://aws.amazon.com/security/security-bulletins/rss/2026-179-aws/](https://aws.amazon.com/security/security-bulletins/rss/2026-179-aws/)

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