CVE-2026-4269: CWE-340 Generation of Predictable Numbers or Identifiers in AWS Bedrock AgentCore Starter Toolkit
CVE-2026-4269 is a high-severity vulnerability in AWS Bedrock AgentCore Starter Toolkit versions before v0.1.13. The issue stems from missing S3 ownership verification during the build process, which may allow a remote actor to inject code and achieve code execution in the AgentCore Runtime. This affects users who built the toolkit after September 24, 2025 on vulnerable versions. Upgrading to version v0.1.13 or later mitigates the issue.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-4269) affects AWS Bedrock AgentCore Starter Toolkit versions prior to v0.1.13. It involves a missing verification step for S3 ownership during the build process, which can be exploited by a remote attacker to inject malicious code. Successful exploitation could lead to arbitrary code execution within the AgentCore Runtime environment. The vulnerability is classified under CWE-340 (Generation of Predictable Numbers or Identifiers) and CWE-283 (Authentication Issues). The CVSS v3.1 base score is 7.5, indicating high severity, with network attack vector, high attack complexity, no privileges required, user interaction required, and high impact on confidentiality, integrity, and availability. The issue is resolved by upgrading to version v0.1.13 or later.
Potential Impact
If exploited, this vulnerability allows remote attackers to inject code during the build process of the toolkit, leading to arbitrary code execution in the AgentCore Runtime. This compromises confidentiality, integrity, and availability of the affected system. The vulnerability affects users who built the toolkit after September 24, 2025 using vulnerable versions. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade the AWS Bedrock AgentCore Starter Toolkit to version v0.1.13 or later. This version includes the necessary S3 ownership verification during the build process to prevent code injection. Users who built the toolkit on vulnerable versions after September 24, 2025 should rebuild using the patched version. No other mitigations are specified.
CVE-2026-4269: CWE-340 Generation of Predictable Numbers or Identifiers in AWS Bedrock AgentCore Starter Toolkit
Description
CVE-2026-4269 is a high-severity vulnerability in AWS Bedrock AgentCore Starter Toolkit versions before v0.1.13. The issue stems from missing S3 ownership verification during the build process, which may allow a remote actor to inject code and achieve code execution in the AgentCore Runtime. This affects users who built the toolkit after September 24, 2025 on vulnerable versions. Upgrading to version v0.1.13 or later mitigates the issue.
CVSS v3.1
Score 7.5high
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-4269) affects AWS Bedrock AgentCore Starter Toolkit versions prior to v0.1.13. It involves a missing verification step for S3 ownership during the build process, which can be exploited by a remote attacker to inject malicious code. Successful exploitation could lead to arbitrary code execution within the AgentCore Runtime environment. The vulnerability is classified under CWE-340 (Generation of Predictable Numbers or Identifiers) and CWE-283 (Authentication Issues). The CVSS v3.1 base score is 7.5, indicating high severity, with network attack vector, high attack complexity, no privileges required, user interaction required, and high impact on confidentiality, integrity, and availability. The issue is resolved by upgrading to version v0.1.13 or later.
Potential Impact
If exploited, this vulnerability allows remote attackers to inject code during the build process of the toolkit, leading to arbitrary code execution in the AgentCore Runtime. This compromises confidentiality, integrity, and availability of the affected system. The vulnerability affects users who built the toolkit after September 24, 2025 using vulnerable versions. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade the AWS Bedrock AgentCore Starter Toolkit to version v0.1.13 or later. This version includes the necessary S3 ownership verification during the build process to prevent code injection. Users who built the toolkit on vulnerable versions after September 24, 2025 should rebuild using the patched version. No other mitigations are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- AMZN
- Date Reserved
- 2026-03-16T14:28:57.619Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 69b84a02771bdb1749186945
Added to database: 3/16/2026, 6:20:50 PM
Last enriched: 6/5/2026, 7:30:03 PM
Last updated: 6/15/2026, 10:28:55 AM
Views: 189
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