CVE-2026-4269
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.
Published:Mar 16, 2026
Last Modified:May 11, 2026
EPS:Mar 16, 2026
EPSS Score:0.00056
CVSS Score:7.5
Affected Products
Vendor
Product
Action
Vendor
Amazon
Product
Bedrock Agentcore Starter Toolkit
Amazon
Bedrock Agentcore Starter Toolkit
Vendor
Aws
Product
Bedrock Agentcore Starter Toolkit
Aws
Bedrock Agentcore Starter Toolkit
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
No CAPEC recorded yet
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
