Amazon AWS API MCP Server up to 1.3.8 improper protection of alternate path

CVSS Meta Temp Score
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CTI Interest Score
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4.3$0-$5k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in Amazon AWS API MCP Server up to 1.3.8. Affected by this vulnerability is an unknown functionality. Such manipulation leads to improper protection of alternate path. This vulnerability is documented as CVE-2026-4270. The attack needs to be performed locally. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Amazon AWS API MCP Server up to 1.3.8. It has been rated as problematic. Affected by this issue is an unknown functionality. The manipulation with an unknown input leads to a improper protection of alternate path vulnerability. Using CWE to declare the problem leads to CWE-424. The product does not sufficiently protect all possible paths that a user can take to access restricted functionality or resources. Impacted is confidentiality. CVE summarizes:

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.

The advisory is shared for download at aws.amazon.com. This vulnerability is handled as CVE-2026-4270 since 03/16/2026. The exploitation is known to be easy. The attack needs to be approached locally. There are neither technical details nor an exploit publicly available.

Upgrading to version 1.3.9 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-12474). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.3

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.5
CNA Vector (AMZN): 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper protection of alternate path
CWE: CWE-424
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: AWS API MCP Server 1.3.9

Timelineinfo

03/16/2026 Advisory disclosed
03/16/2026 +0 days CVE reserved
03/16/2026 +0 days VulDB entry created
03/21/2026 +5 days VulDB entry last update

Sourcesinfo

Advisory: aws.amazon.com
Status: Confirmed

CVE: CVE-2026-4270 (🔒)
GCVE (CVE): GCVE-0-2026-4270
GCVE (VulDB): GCVE-100-351296
EUVD: 🔒

Entryinfo

Created: 03/16/2026 19:11
Updated: 03/21/2026 13:41
Changes: 03/16/2026 19:11 (75), 03/17/2026 23:28 (1), 03/21/2026 13:41 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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