CVE-2026-4270 | BDVDB-2026-320760 Detail

AWSAWS API MCP Server

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.

Impact#

CAPEC-6 Argument Injection

Weaknesses#

CWE-424 Improper Protection of Alternate Path

References#

Exploit#

No public exploit known

History#

Version 12026-03-16Record published in the CVE List.

Published

Published: 2026-03-16
Last modified: 2026-03-16

Vendor information

Vendor: AWS
Product: AWS API MCP Server

All AWS vulnerabilities

Score

5.5 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 3.1.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
>= 0.2.14 and < 1.3.9
Fixed
1.3.9

Scoring System

CVSS v4.0

6.8 Medium

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

Metric breakdown
Attack Vector	Local
Attack Complexity	Low
Attack Requirements	None
Privileges Required	None
User Interaction	Passive
Vulnerable System Confidentiality	High
Vulnerable System Integrity	None
Vulnerable System Availability	None
Subsequent System Confidentiality	None
Subsequent System Integrity	None
Subsequent System Availability	None

CVSS v3.1

5.5 Medium

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Metric breakdown
Attack Vector	Local
Attack Complexity	Low
Privileges Required	None
User Interaction	Required
Scope	Unchanged
Confidentiality	High
Integrity	None
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).