CVE-2026-4270
MEDIUMAWS API MCP Server 0.2.14-1.3.8 - File Access Restriction Bypass
Title source: manualDescription
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.
References (2)
Core 2
Core References
Vendor Advisory vendor-advisory
https://aws.amazon.com/security/security-bulletins/2026-007-AWS/
Scores
CVSS v3
5.5
EPSS
0.0002
EPSS Percentile
5.6%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-424
Status
published
Products (3)
amazon/aws_api_mcp_server
0.2.14 - 1.3.9
AWS/AWS API MCP Server
0.2.14 - 1.3.9
pypi/awslabs.aws-api-mcp-server
0.2.14 - 1.3.9PyPI
Published
Mar 16, 2026
Tracked Since
Mar 16, 2026