In plain language
What this advisory means
AWS CDK is a tool that helps developers build and deploy cloud infrastructure using code. A security issue was found where specially crafted Dockerfiles used during the asset packaging step could insert hidden linked files (symlinks) into the packaged output without those symlinks being part of the original input. This could let unintended files or directories slip into deployments.
Technical explanation
How the issue affects the environment
The vulnerability (CVE-2026-107608) involves improper handling of symbolic links (symlinks) during the asset bundling process in aws-cdk-lib versions before 2.267.0 when using Docker-based bundling. Specifically, Dockerfiles could be constructed to place symlinked files or directories into the bundling output even if those symlinks were not in the declared input set. This flawed symlink resolution in the asset bundling output could cause unanticipated files to be included in deployment bundles, potentially enabling unintended code or data to propagate through infrastructure deployments.
Operational impact
Why teams should care
This issue may result in unexpected or unauthorized files being included in cloud infrastructure deployments. Such inclusion can lead to security risks including the deployment of unintended code, causing operational reliability or security breaches. Organizations using affected AWS CDK versions should address this vulnerability to maintain the integrity of their cloud infrastructure.
Immediate action
Upgrade aws-cdk-lib to version 2.267.0 or later to incorporate the fix that properly handles symlink resolution in asset bundling output. For derivative or forked versions of aws-cdk-lib, apply equivalent patches to address this vulnerability.
Affected and fixed releases
Temporary risk reduction
If immediate upgrading is not possible, audit all Docker bundling containers and their dependencies to ensure they contain only trusted code. This reduces the risk of unintended or malicious code execution within the bundling environment, limiting the possibility of injecting unexpected symlinked files.
Evidence and validation checklist
- Official AWS Security Bulletin for CVE-2026-107608 dated 2026-10-08
- Details and resolution information published by AWS Security Bulletins
- Upgrade recommendation to aws-cdk-lib version 2.267.0
- Guidance for auditing Docker bundling containers as a workaround
Authoritative reference
AWS Security Bulletins
QCS detected and normalized this record from the official source. Vendor guidance remains authoritative.