Dev Teams Must Upgrade AWS Amplify Codegen UI to Patch Authenticated Code Injection Flaw

Authenticated users can execute arbitrary JavaScript code in applications using the @aws-amplify/codegen-ui-react library due to a code injection flaw identified as CVE-2026-18245. This vulnerability exists within the amplify-codgen-ui-react package and activates during the component rendering and build process. According to the AWS Security Bulletins advisory published on July 30, 2026, the issue requires immediate attention from developers maintaining AWS Amplify projects that rely on this library for generating React components and themes from schema definitions.

What is the scope of this vulnerability?

The flaw affects the @aws-amplify/codegen-ui-react package, specifically allowing authenticated users to run arbitrary JavaScript code. This execution capability occurs during the component rendering and build process, potentially compromising the integrity of the application. The advisory classifies the bulletin as important, requiring attention from all users of the affected library. There are no workarounds available; the only mitigation is upgrading to the patched version.

Which version fixes the issue?

AWS addressed the issue in @aws-amplify/codegen-ui-react version 2.20.6. The security bulletin explicitly recommends upgrading to this latest version. Additionally, developers who have forked or created derivative code from the library must ensure that their custom versions incorporate the new fixes. Failure to update leaves applications vulnerable to arbitrary code execution by authenticated users.

Who reported this vulnerability?

George Chen reported this issue to AWS. He collaborated with the company through the coordinated issue disclosure process. AWS thanked him for his contribution to identifying and helping resolve the security flaw. The coordinated process ensures that vulnerabilities are addressed responsibly before public disclosure, allowing vendors time to prepare patches and users time to apply them.

What should developers do next?

Developers should immediately check their project dependencies for the @aws-amplify/codegen-ui-react package. If the version is older than 2.20.6, they must upgrade to the latest version. Teams should also review any forked or derivative code to ensure it includes the necessary fixes. Since no workarounds exist, upgrading is the only way to mitigate the risk associated with CVE-2026-18245.

What analysts watch for

Security teams usually monitor build logs and runtime environments for unexpected JavaScript execution patterns in applications using code generation libraries. Analysts check whether authenticated users can inject malicious payloads into schema definitions that render as executable code. They examine network traffic for anomalous requests originating from build processes. Teams also review access controls to ensure that only trusted users can submit schema definitions, reducing the attack surface for code injection attempts.

Background: Security bulletins

Security bulletins provide the context needed to prioritize patches. They translate technical flaws into business risk, allowing teams to decide what to fix first. Without this structured information, organizations patch randomly or not at all, leaving known gaps open to exploitation.

Read the full guide: How Security Bulletins Drive Real Patching Decisions

What to do and how to stay safe: AWS

• Audit your project dependencies to identify if you are using @aws-amplify/codegen-ui-react versions prior to 2.20.6.
• Upgrade to version 2.20.6 or later to apply the fix for CVE-2026-18245.
• Review any forked or derivative code to ensure it incorporates the security fixes from the official release.
• Monitor application logs for signs of arbitrary JavaScript execution during component rendering or build processes.

Step-by-step guide: How Vulnerability Scanning Works: The Hidden Mechanics and Limits

General security guidance from the Sandbox Desk newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

What is CVE-2026-18245?

CVE-2026-18245 is a code injection vulnerability in the @aws-amplify/codegen-ui-react package that allows authenticated users to run arbitrary JavaScript code during component rendering and build processes.

Is there a workaround for this vulnerability?

No, there are no workarounds. The only mitigation is to upgrade to @aws-amplify/codegen-ui-react version 2.20.6 or later.

Who reported this vulnerability?

George Chen reported this issue through the coordinated issue disclosure process.