Deprecation Warning: punycode module in AWS CDK logs

[Sivakumar-CD]

Issue Description

I am using aws-cdk-lib and see the following deprecation warning in CloudWatch logs:

ERROR (node:9) [DEP0040] DeprecationWarning: The punycode module is deprecated. Please use a userland alternative instead.
(Use node --trace-deprecation ... to show where the warning was created)

• I checked my dependencies using yarn why punycode, and the module is used by aws-cdk-lib.
• I am not directly using punycode in my code.
• The issue happens even after updating AWS CDK.

Steps to Reproduce

1. Deploy an AWS CDK stack using Node.js.
2. Observe CloudWatch logs where this deprecation warning appears.

Expected Behavior

• AWS CDK should not use deprecated dependencies.

Environment

• AWS CDK Version: 2.1005.0
• Node.js Version:v23.9.0

Workaround

• I have tried updating AWS CDK (yarn upgrade aws-cdk-lib), but the issue persists.

Additional Context

• The punycode module was deprecated in Node.js 7 and removed in Node.js 17.
• The dependency tree shows it is required by aws-cdk-lib and ajv -> uri-js -> punycode.

Could AWS CDK remove this deprecated dependency?

[lohmuller]

@Sivakumar-CD
It looks like you're using Node.js v23, which is not currently an LTS version.

AWS CDK officially supports and is tested with LTS versions like Node.js 20.x and 22.x.

The warning you're seeing is due to the punycode module being deprecated in Node.js 7 and removed from the core in Node.js 17 and above, requiring an external package.

Some deep dependencies (like ajv -> uri-js) still try to access the native punycode module.

Until these dependencies are updated upstream, the most stable option is to use Node.js 20 or 22 (LTS) and install the punycode package (npm install punycode) or update dependencies like ajv and uri-js to versions that don't rely on the native punycode.

You can switch with nvm:

nvm install 22
nvm use 22

if it doesnt work, you can try to clean the cache/Modules, maybe you installed an old version

yarn upgrade aws-cdk-lib@latest
rm -rf node_modules yarn.lock
yarn install