Is CVE-2026-4270 actively exploited?

No active exploitation of CVE-2026-4270 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-4270 be exploited remotely?

No. CVE-2026-4270 requires local access to exploit.

What is the CVSS score of CVE-2026-4270?

CVE-2026-4270 has a CVSS score of 5.5 (MEDIUM).

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MEDIUM

CVE-2026-4270

CWE-424Published: March 16, 2026· Updated: Mar 17, 2026

5.5

CVSS v3.1

EPSS:0.01%probability of exploitation in 30 daysPercentile:1.7th

Official Description

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 file contents in the MCP client application context.

To remediate this issue, users should upgrade to version 1.3.9.

NVD Source

Technical Analysis

CVE-2026-4270 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 5.5.