Public vulnerability disclosure

CVE-2026-115845

Incomplete validation in the run_script Python sandbox in AWS MCP Server

publishedCWE-184

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.

Investigate in Cyber JSON Markdown

Technical severity6.4 mediumCVSS 3.1 · CNA: AMZN

Published2026-10-23Source updated 2026-11-02

Collected2026-11-022 attributed sources

Fixes and workarounds

No remediation reported in collected sources.

Missing remediation information is not evidence that no patch exists.

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
AWS MCP Server AWS	Version not specified (affected, custom) Other versions: unaffected	CNA: AMZN

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 6.4 medium	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N`	CNA: AMZN
4.0 / 5.3 medium	`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`	CNA: AMZN

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://aws.amazon.com/security/security-bulletins/2026-149-aws/CNA: AMZN · vendor-advisory