CVE-2026-4269

HIGH

Improper S3 ownership verification in Bedrock AgentCore Starter Toolkit

Title source: cna
STIX 2.1

Description

A missing S3 ownership verification in the Bedrock AgentCore Starter Toolkit before version v0.1.13 may allow a remote actor to inject code during the build process, leading to code execution in the AgentCore Runtime. This issue only affects users of the Bedrock AgentCore Starter Toolkit before version v0.1.13 who build or have built the Toolkit after September 24, 2025. Any users on a version >=v0.1.13, and any users on previous versions who built the toolkit before September 24, 2025 are not affected. To remediate this issue, customers should upgrade to version v0.1.13.

References (2)

Core 2

Scores

CVSS v3 7.5
EPSS 0.0007
EPSS Percentile 20.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-283 CWE-340
Status published
Products (3)
amazon/bedrock_agentcore_starter_toolkit < 0.1.13
AWS/Bedrock AgentCore Starter Toolkit 0.1.0 - 0.1.13
pypi/bedrock-agentcore-starter-toolkit 0 - 0.1.13PyPI
Published Mar 16, 2026
Tracked Since Mar 17, 2026