MSK Encryption Weak

What this rule checks

Detects MSK clusters without TLS for client-broker traffic, without inter-broker encryption, or using AWS-managed keys for at-rest encryption.

How to fix it

1. 1Set ClientBroker to TLS in EncryptionInTransit
2. 2Set InCluster to true in EncryptionInTransit
3. 3Specify DataVolumeKMSKeyId for at-rest encryption

import { aws_msk as msk, aws_ec2 as ec2 } from 'aws-cdk-lib';

const vpc = new ec2.Vpc(this, 'Vpc');
new msk.CfnCluster(this, 'Cluster', {
  clusterName: 'events',
  kafkaVersion: '3.5.1',
  numberOfBrokerNodes: 3,
  brokerNodeGroupInfo: {
    instanceType: 'kafka.m5.large',
    clientSubnets: vpc.privateSubnets.map((s) => s.subnetId),
  },
  encryptionInfo: {
    encryptionInTransit: { clientBroker: 'PLAINTEXT', inCluster: false },
  },
});

import { aws_msk as msk, aws_ec2 as ec2, aws_kms as kms } from 'aws-cdk-lib';

const vpc = new ec2.Vpc(this, 'Vpc');
new msk.CfnCluster(this, 'Cluster', {
  clusterName: 'events',
  kafkaVersion: '3.5.1',
  numberOfBrokerNodes: 3,
  brokerNodeGroupInfo: {
    instanceType: 'kafka.m5.large',
    clientSubnets: vpc.privateSubnets.map((s) => s.subnetId),
  },
  encryptionInfo: {
    encryptionInTransit: { clientBroker: 'TLS', inCluster: true },
    encryptionAtRest: { dataVolumeKmsKeyId: new kms.Key(this, 'MskKey').keyId },
  },
});

CDK Insights pinpoints the exact file and line in your CDK source for every finding, so you can jump straight to the fix.

Affected resource types

Intentional? Suppress this finding

Sometimes a flag is deliberate — a genuinely public endpoint, say. You can dismiss msk-encryption-weak and the reason is kept in the report, not silently hidden.

In .cdk-insights.json:

{
  "ignoreRules": [
    { "id": "msk-encryption-weak", "reason": "Why this is intentional" }
  ]
}

Or inline in your CDK code:

Validations.of(scope).acknowledge({
  id: 'cdk-insights::msk-encryption-weak',
  reason: 'Why this is intentional',
});

Use the rule ID msk-encryption-weak shown above — not the CDK-* ID from SARIF / GitHub code scanning. To dismiss every finding on one construct instead, use ignorePaths. Suppression docs →

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