CVE-2026-4269 HIGH

CVE-2026-4269: Improper S3 ownership verification in Bedrock AgentCore Starter Toolkit

Vendor Aws
Product Bedrock AgentCore Starter Toolkit
Weakness CWE-340
Published March 16, 2026
Last update March 16, 2026
View on NVD All CVEs

CVSS base score

7.5/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction Required
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 16, 2026 CVE published
March 16, 2026 Record updated