Vulnerability · Published Oct 23, 2026 · Assigned by AMZN
CVE-2026-115845Incomplete validation in the run_script Python sandbox in AWS MCP Server
Medium 6.4
In plain English
A medium-severity security flaw in AWS MCP Server from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).
Severity (CVSS 3.1)6.4Medium
Exploit odds (30 days)0.3%top 76.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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 products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| AWS | AWS MCP Server | N/A |
Weakness: CWE-184 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
References
- https://aws.amazon.com/security/security-bulletins/2026-149-aws/ vendor-advisory