What is CVE-2026-4270?

CVE-2026-4270 is a medium-severity vulnerability in Amazon Aws_api_mcp_server, classified under CWE-424. CVSS score: 5.5/10. Published 2026-03-16.

How severe is CVE-2026-4270?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Amazon Aws_api_mcp_server

CVE-2026-4270

Improper Protection of Alternate Path exists in the no-access and workdir feature of the AWS API MCP Server versions >= 0.2.14 and < 1.3.9 on all platforms may allow the bypass of intended file access restriction and expose arbitrary local…

EPSS: 0.000 (5.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

Affected products

Amazon Aws_api_mcp_server
Aws Api Mcp Server — versions 0.2.14

Weakness classification (CWE)

CWE-424

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory, Vendor Advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (Third Party Advisory, patch)

Frequently asked questions

What is CVE-2026-4270?: CVE-2026-4270 is a medium-severity vulnerability in Amazon Aws_api_mcp_server, classified under CWE-424. CVSS score: 5.5/10. Published 2026-03-16.
How severe is CVE-2026-4270?: Medium severity. CVSS v3 base score is 5.5 out of 10.