Event Source Mapping Missing Required IAM Permissions

What this rule checks

An AWS::Lambda::EventSourceMapping polls an in-template SQS queue, Kinesis stream, or DynamoDB stream but the function execution role lacks the documented required actions (e.g. sqs:ReceiveMessage / DeleteMessage / GetQueueAttributes). The mapping fails to create or the poller fails with AccessDenied.

How to fix it

1. 1Grant the poller permissions in CDK: queue.grantConsumeMessages(fn), stream.grantRead(fn), or table.grantStreamRead(fn)
2. 2Or attach the matching AWS managed policy: AWSLambdaSQSQueueExecutionRole, AWSLambdaKinesisExecutionRole, or AWSLambdaDynamoDBExecutionRole
3. 3The Lambda service polls the source with the function's execution role, so the role itself needs these actions

import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as sqs from 'aws-cdk-lib/aws-sqs';

const queue = new sqs.Queue(this, 'Jobs');

const worker = new lambda.Function(this, 'Worker', {
  runtime: lambda.Runtime.NODEJS_20_X,
  handler: 'index.handler',
  code: lambda.Code.fromInline('exports.handler = async () => {};'),
});

new lambda.CfnEventSourceMapping(this, 'Mapping', {
  functionName: worker.functionName,
  eventSourceArn: queue.queueArn,
});

import * as lambda from 'aws-cdk-lib/aws-lambda';
import { SqsEventSource } from 'aws-cdk-lib/aws-lambda-event-sources';
import * as sqs from 'aws-cdk-lib/aws-sqs';

const queue = new sqs.Queue(this, 'Jobs');

const worker = new lambda.Function(this, 'Worker', {
  runtime: lambda.Runtime.NODEJS_20_X,
  handler: 'index.handler',
  code: lambda.Code.fromInline('exports.handler = async () => {};'),
});

worker.addEventSource(new SqsEventSource(queue));

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Affected resource types

Intentional? Suppress this finding

Sometimes a flag is deliberate — a genuinely public endpoint, say. You can dismiss TL-PERM-002 and the reason is kept in the report, not silently hidden.

In .cdk-insights.json:

{
  "ignoreRules": [
    { "id": "TL-PERM-002", "reason": "Why this is intentional" }
  ]
}

Or inline in your CDK code:

Validations.of(scope).acknowledge({
  id: 'cdk-insights::TL-PERM-002',
  reason: 'Why this is intentional',
});

Use the rule ID TL-PERM-002 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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