# CVE-2026-87913: Missing S3 bucket ownership verification in the AWS Security Agent MCP server

> CVE-2026-87913: Missing S3 bucket ownership verification in the AWS Security Agent MCP server. CVSS 5.9 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-87913
Last updated: 2026-09-10T19:54:25Z

- Published: 2026-09-10 15:43 UTC · Updated: 2026-09-10 19:54 UTC · Assigner: AMZN
- CVSS: 5.9 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N
- EPSS: 0.44%, 38th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-283, CWE-341

## Description

A missing S3 bucket ownership verification in the AWS Security Agent MCP server before 0.2.0 version might allow remote attackers to obtain the private source archive of a scanned workspace, including credentials and infrastructure state contained in that archive, via a pre-registered storage bucket whose name is derived from a publicly known account identifier. To remediate this issue, users should upgrade to version 0.2.0. Users should also verify that the scan output bucket in their account is owned by their own account, because upgrading does not release a bucket name that a third party has already registered.

## Affected vendors and products

- AWS: AWS Security Agent 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-2026-87913)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-87913)
- [https://aws.amazon.com/security/security-bulletins/2026-105-aws/](https://aws.amazon.com/security/security-bulletins/2026-105-aws/)
- [https://github.com/awslabs/mcp/security/advisories/GHSA-3jxw-vj8m-8x77](https://github.com/awslabs/mcp/security/advisories/GHSA-3jxw-vj8m-8x77)
- [https://pypi.org/project/awslabs.security-agent-mcp-server/0.2.0/?refid=d8ec3b19-0f37-4f8c-8c12-189f913e205c](https://pypi.org/project/awslabs.security-agent-mcp-server/0.2.0/?refid=d8ec3b19-0f37-4f8c-8c12-189f913e205c)

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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-2026-87913 · Markdown: https://rewindex.com/cve/CVE-2026-87913.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-87913 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:15:57.006Z