CVE-2026-4270

MEDIUM EPSS 3.0%
Published Mar 16, 20263mo ago · Modified Jun 17, 20262w ago
6.8 CVSS 4.0
Medium
Find Similar
Published Mar 16, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
6.8
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Local
Attack Complexity Low
Privileges Required None
User Interaction P
Scope X

Threat Intelligence

EPSS Exploit Probability
3.0% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-424

Affected Products 1

VendorProductVersionRange
amazonaws_api_mcp_server*≥0.2.14  –  <1.3.9

References 2

  • aws.amazon.com https://aws.amazon.com/security/security-bulletins/2026-007-AWS/
    Vendor Advisory
  • pypi.org https://pypi.org/project/awslabs.aws-api-mcp-server/1.3.9/
    Third Party Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.