---
id: CVE-2026-115845
title: Incomplete validation in the run_script Python sandbox in AWS MCP Server
summary: >-
  An incomplete list of disallowed inputs in the Python code validator of the
  run_script tool in AWS MCP Server might allow an authenticated remote user to
  execute arbitrary code within their own isolated session environment via a
  crafted …
severity: medium
cvss: 6.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-184
vendor: AWS
product: AWS MCP Server
affected:
  - mcp_server N/A
published: '2026-10-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T19:04:44.790Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-115845'
references:
  - url: 'https://aws.amazon.com/security/security-bulletins/2026-149-aws/'
tags:
  - cve.org
ingestedAt: '2026-10-23T19:35:13.444Z'
---

## Overview

An incomplete list of disallowed inputs in the Python code validator of the run_script tool in AWS MCP Server might allow an authenticated remote user to execute arbitrary code within their own isolated session environment via a crafted script.



AWS fixed this issue service-side. No customer action is required.

## Affected

- `mcp_server N/A`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.