AWS fixed a critical CodeBuild misconfiguration within 48 hours that exposed GitHub repositories to potential hijacking, security researchers revealed earlier this year.
Security firm Wiz discovered the vulnerability, dubbed "CodeBreach," in August 2025 and reported it to Amazon Web Services. The cloud provider patched the issue by September 2025, but public disclosure only occurred in January 2026.
The flaw stemmed from a regular expression misconfiguration in AWS CodeBuild's webhook validation system. This allowed attackers to bypass actor ID checks and potentially gain unauthorized access to four AWS-owned GitHub repositories.
One exposed repository contained the AWS JavaScript SDK, which powers the AWS Management Console used by millions of developers and enterprises worldwide.
Compromise could have enabled supply chain attacks distributing backdoored software updates through official channels.
Wiz researchers detailed how the regex pattern failed to strictly enforce expected formats, enabling unauthenticated attackers to trigger builds and potentially alter code in critical repositories. The vulnerability specifically targeted the AWS management console supply chain.
"AWS implemented fixes within 48 hours of initial disclosure," according to company statements.
The cloud provider rotated credentials, secured build environments, and added additional safeguards to prevent similar issues.
No evidence suggests CodeBreach was exploited in the wild before patching. AWS audited logs of all public build repositories and associated CloudTrail logs, confirming no unauthorized access occurred.
The incident highlights supply chain risks in interconnected cloud development environments. AWS CodeBuild automates building and testing code, making it a critical component in CI/CD pipelines across the industry.
Security experts recommend developers review their own CodeBuild configurations, anchor webhook regex filters, and limit token privileges.
The vulnerability serves as a reminder that misconfigurations in high-stakes environments can cascade into widespread security threats, similar to other recent security flaws exposing systems to hijacking.
Industry parallels include the SolarWinds compromise, where compromised software updates led to widespread infiltration. CodeBreach could have affected applications relying on AWS services.
AWS maintains the issue was project-specific rather than a flaw in the CodeBuild service itself. The company has updated documentation and implemented automated checks following the incident.
Public disclosure occurred in January 2026, several months after AWS addressed the vulnerability. Both AWS and Wiz now recommend users ensure untrusted pull requests cannot trigger privileged build pipelines.
For enterprises relying on AWS, the incident underscores the importance of supply chain security hygiene. Implementing software bill of materials (SBOM) and vulnerability scanning becomes increasingly critical as cloud dependencies grow.
The CodeBreach vulnerability demonstrates how small configuration oversights can jeopardize core infrastructure in cloud computing environments.
While AWS averted disaster through prompt action, the close call emphasizes the need for continuous security improvement across the industry.
