5.5Medium
CVE-2026-4270AWS API MCP File Access Restriction Bypass
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.
Weakness (CWE):
CWE-424
Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.
Affected products and versions
| Vendor | Product | Versions | |
|---|---|---|---|
| amazon | aws api mcp server | 0.2.14 – < 1.3.9 | |
| AWS | AWS API MCP Server | 0.2.14 – < 1.3.9 |
References and patches
- https://aws.amazon.com/security/security-bulletins/2026-007-AWS/ vendor-advisoryVendor Advisory
- https://pypi.org/project/awslabs.aws-api-mcp-server/1.3.9/ patchThird Party Advisory
CPE matches (NVD) (1)
cpe:2.3:a:amazon:aws_api_mcp_server:*:*:*:*:*:python:*:*≥ 0.2.14 < 1.3.9