AWS Fixes Privilege Escalation in Serverless CI/CD Toolchain Sample App
A flaw in AWS’s serverless toolchain sample allowed repository users to access resources outside the application stack in the same account.
Key points
- CVE-2026-112407 carries a CVSS score of 8.8, rated as high severity by the National Vulnerability Database.
- The vulnerability affects AWS CICD-toolchain-for-serverless-applications versions 1.0.7 through 1.0.10.
- AWS released version 1.0.11 on October 20, 2026, to address the incorrect privilege assignment.
Amazon Web Services released a security update on October 20, 2026, to fix a high-severity privilege escalation flaw in its serverless application toolchain sample. The vulnerability, tracked as CVE-2026-112407, allows authenticated users with repository push access to modify resources outside the intended application stack.
At a glance
- CVE
- CVE-2026-112407
- Product
- AWS CICD-toolchain-for-serverless-applications
- CVSS
- 8.8 High
- Weakness
- CWE-266
- Exploited
- No known exploitation
The National Vulnerability Database assigns the flaw a CVSS score of 8.8. According to the advisory, the issue stems from an incorrect privilege assignment in the Identity and Access Management policy. This misconfiguration enables attackers to leverage application templates deployed by the toolchain pipeline to escalate their permissions within the same AWS account.
Context and Background
AWS describes the affected software as a sample application that provisions continuous integration and delivery pipelines for serverless applications. The tool is distributed through the AWS Serverless Application Repository. The security bulletin, identified as 2026-141-AWS, was published at 1:30 PM PDT on October 20, 2026.
The company classified the content type as important, requiring attention from administrators. The advisory notes that the flaw existed in versions prior to 1.0.11. AWS credited Changli from Xidian University for collaborating on the issue through the coordinated vulnerability disclosure process.
Who Is Affected
Users of AWS CICD-toolchain-for-serverless-applications versions 1.0.7 through 1.0.10 are impacted by this vulnerability. The flaw specifically targets remote authenticated users who possess push access to the application source repository. These users can exploit the weakness to access or modify resources that lie outside the specific application stack.
The risk is confined to the same AWS account where the toolchain is deployed. However, the ability to modify resources outside the stack represents a significant breach of the principle of least privilege. Organizations using forked or derivative code from the sample application must also apply the fixes.
What should you do?
Administrators should upgrade their existing toolchain stacks to version 1.0.11 or later immediately. The update addresses the incorrect IAM policy assignment that allowed the privilege escalation. AWS also recommends ensuring that any custom forks of the sample application incorporate the new security fixes.
Organizations should audit their source repository access controls to limit push permissions. Reviewing IAM policies associated with CI/CD pipelines can help identify similar misconfigurations. Monitor AWS Security Bulletins for further updates on this vulnerability or related issues in serverless application repositories.
Background: Coordinated vulnerability disclosure
Coordinated vulnerability disclosure reveals software flaws to vendors before public release. Small teams must patch during this quiet period. Monitor vendor security pages, prioritize critical updates, and verify that your IT provider tracks these disclosures to prevent exploitation of known weaknesses before public patches arrive.
Read the full guide: Coordinated Vulnerability Disclosure for Small Teams
What to do and how to stay safe: AWS
- Upgrade AWS CICD-toolchain-for-serverless-applications to version 1.0.11 or later to patch the privilege escalation flaw.
- Audit IAM policies for CI/CD pipelines to ensure they follow the principle of least privilege and do not grant excessive permissions.
- Review access controls for source repositories to restrict push access to only those who strictly require it for deployment.
- Check for any forked or derivative versions of the toolchain and apply the corresponding security fixes to those codebases.
Step-by-step guide: Detect CI/CD Pipeline Vulnerabilities: Signals, Blind Spots and Tools
General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
What is the CVSS score for CVE-2026-112407?
The National Vulnerability Database rates the vulnerability with a CVSS score of 8.8, which is considered high severity.
Which versions of the toolchain are affected?
Versions 1.0.7 through 1.0.10 of AWS CICD-toolchain-for-serverless-applications are vulnerable to this privilege escalation issue.
Is there a fix available for this vulnerability?
Yes, AWS released version 1.0.11 on October 20, 2026, which addresses the incorrect privilege assignment in the IAM policy.
