Description
Missing token audience validation in the OAuth authentication mode of AWS API MCP Server before version 1.6.0 might allow local users to run AWS operations with the server's configured AWS credentials via an access token issued to another application by the same identity provider.
To remediate this issue, users should upgrade to version 1.6.0 and configure the expected token audience or client ID for the server.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| AWS | aws-api-mcp-server | 1.3.0 – < 1.6.0 | 1.6.0 |
References
- https://pypi.org/project/awslabs.aws-api-mcp-server/1.6.0/ release-notes patch
- https://github.com/awslabs/mcp/security/advisories/GHSA-4prq-p2x5-w9fh third-party-advisory
- https://aws.amazon.com/security/security-bulletins/2026-152-aws/ vendor-advisory