Medium severity5.5NVD Advisory· Published Mar 16, 2026· Updated May 21, 2026
CVE-2026-4270
CVE-2026-4270
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
awslabs.aws-api-mcp-serverPyPI | >= 0.2.14, < 1.3.9 | 1.3.9 |
awslabs-aws-api-mcp-serverPyPI | >= 0.2.14, < 1.3.9 | 1.3.9 |
Affected products
3- cpe:2.3:a:amazon:aws_api_mcp_server:*:*:*:*:*:python:*:*Range: >=0.2.14,<1.3.9
- Range: 0.2.14
Patches
Vulnerability mechanics
References
8- aws.amazon.com/security/security-bulletins/2026-007-AWS/nvdVendor Advisory
- github.com/advisories/GHSA-2cpp-j2fc-qhp7ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-4270ghsaADVISORY
- pypi.org/project/awslabs.aws-api-mcp-server/1.3.9/nvdThird Party Advisory
- aws.amazon.com/security/security-bulletins/2026-007-AWSghsaWEB
- github.com/awslabs/mcp/security/advisories/GHSA-2cpp-j2fc-qhp7ghsaWEB
- github.com/pypa/advisory-database/tree/main/vulns/awslabs-aws-api-mcp-server/PYSEC-2026-162.yamlghsaWEB
- pypi.org/project/awslabs.aws-api-mcp-server/1.3.9ghsaWEB
News mentions
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