# CVE-2026-16584: AWS API MCP Server Security Policy Bypass via Startup Failure

> CVE-2026-16584: AWS API MCP Server Security Policy Bypass via Startup Failure. CVSS 7.0 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-16584
Last updated: 2026-10-24T13:10:00Z

- Published: 2026-07-23 15:34 UTC · Updated: 2026-10-24 13:10 UTC · Assigner: AMZN
- CVSS: 7.0 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS: 0.23%, 13th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-455

## Description

Improper handling of an initialization failure in AWS API MCP Server from 0.2.13 through 1.3.46 might allow an actor to bypass the user-configured security policy and execute AWS API operations that the policy was set to deny or gate. When initialization of the security policy enforcement data fails at server startup, the policy check is skipped for the lifetime of the process. IAM permissions on the configured credentials remain in effect and are unaffected. To remediate this issue, users should upgrade to version 1.3.47.

## Affected vendors and products

- AWS: aws-api-mcp-server

## Tracked companies

- [Amazon Web Services](https://rewindex.com/company/aws.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-16584)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-16584)
- [https://aws.amazon.com/security/security-bulletins/2026-063-aws/](https://aws.amazon.com/security/security-bulletins/2026-063-aws/)
- [https://github.com/awslabs/mcp/security/advisories/GHSA-29w2-fq35-v728](https://github.com/awslabs/mcp/security/advisories/GHSA-29w2-fq35-v728)
- [https://pypi.org/project/awslabs.aws-api-mcp-server/1.3.47/](https://pypi.org/project/awslabs.aws-api-mcp-server/1.3.47/)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-16584 · Markdown: https://rewindex.com/cve/CVE-2026-16584.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-16584 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:14:01.073Z