ECS Task Definition Uses Mutable Image Tag

What this rule checks

Detects ECS task definition containers referencing an image by the mutable "latest" tag or no tag at all, so deployments are not reproducible and a changed upstream image can land without a code change.

How to fix it

1. 1Reference container images by an immutable tag (release version or git SHA)
2. 2Or pin the image by @sha256 digest so every deployment runs the exact tested image

import { App, Stack } from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as ecs from 'aws-cdk-lib/aws-ecs';

// FLAGGED: container image pinned to the mutable 'latest' tag.
new ecs.CfnTaskDefinition(this, 'Task', {
  cpu: '256',
  memory: '512',
  containerDefinitions: [
    {
      name: 'app',
      image: 'public.ecr.aws/nginx/nginx:latest',
      logConfiguration: {
        logDriver: 'awslogs',
        options: { 'awslogs-group': '/ecs/app', 'awslogs-region': 'us-east-1', 'awslogs-stream-prefix': 'app' },
      },
    },
  ],
});

import { App, Stack } from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as ecs from 'aws-cdk-lib/aws-ecs';

// FIXED: image pinned to an immutable version tag.
new ecs.CfnTaskDefinition(this, 'Task', {
  cpu: '256',
  memory: '512',
  containerDefinitions: [
    {
      name: 'app',
      image: 'public.ecr.aws/nginx/nginx:1.27.3',
      logConfiguration: {
        logDriver: 'awslogs',
        options: { 'awslogs-group': '/ecs/app', 'awslogs-region': 'us-east-1', 'awslogs-stream-prefix': 'app' },
      },
    },
  ],
});

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 ecs-task-definition-mutable-image-tag and the reason is kept in the report, not silently hidden.

In .cdk-insights.json:

{
  "ignoreRules": [
    { "id": "ecs-task-definition-mutable-image-tag", "reason": "Why this is intentional" }
  ]
}

Or inline in your CDK code:

Validations.of(scope).acknowledge({
  id: 'cdk-insights::ecs-task-definition-mutable-image-tag',
  reason: 'Why this is intentional',
});

Use the rule ID ecs-task-definition-mutable-image-tag 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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