p PatchFirst

CVE-2026-4270

CVE-2026-4270 · AWS API MCP File Access Restriction Bypass

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 6.8 · Medium · EPSS 0.1% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • aws api mcp server

    Versions
    • ≥ 0.2.14, < 1.3.9: Affected (custom)

    Update to 1.3.9

  • awslabs-aws-api-mcp-server PyPI

    Versions
    • 0.2.14
    • 0.3.0
    • 0.3.1
    • 0.3.2
    • 0.3.3
    • 0.3.4
    • 1.0.0
    • 1.0.1
    • 1.0.2
    • 1.1.0
    • 1.1.1
    • 1.1.2
    • 1.1.3
    • 1.1.4
    • 1.1.5
    • 1.1.6
    • 1.1.7
    • 1.1.8
    • 1.2.0
    • 1.2.1
    • 1.2.2
    • 1.2.3
    • 1.3.0
    • 1.3.1
    • 1.3.2
    • 1.3.3
    • 1.3.4
    • 1.3.5
    • 1.3.6
    • 1.3.7
    • 1.3.8
    Affected ranges
    • ECOSYSTEM: ≥ 0.2.14, < 1.3.9

    Update to 1.3.9

Original sources

Check your server →