Docker Hub Flaw Exposes Container Registries to Impersonation and Image Tampering

A critical vulnerability, CVE-2026-105445, has been discovered and patched in Docker Hub. The flaw existed for over two years, from August 26, 2024, until its fix on September 30, 2026. The vulnerability allowed an attacker to gain unauthorized access to a target user's container repositories by exploiting a weakness in how Docker Hub reassigned Personal Access Tokens (PATs) during the conversion of a personal account to an organization. Specifically, when a personal account was converted into an organization, the PATs associated with the original account were transferred to the new organization owner without revoking the original secret or requiring confirmation from the new owner. This meant an attacker could create an account, generate a PAT, then convert that account to an organization and designate a target user as the owner, thereby gaining control over the target's PAT and access to their repositories. This vulnerability is significant because it directly impacts the integrity of the software supply chain. Docker Hub is a central repository for container images, and the ability for an attacker to push, pull, or delete images as another user could lead to the injection of malicious code into widely used software. This could result in widespread compromise of applications that rely on these images. For DevOps and cloud engineers, this underscores the critical importance of verifying the authenticity and integrity of all container images, even those from seemingly trusted sources. The potential for an attacker to publish malicious images under a legitimate name poses a severe threat to any organization consuming public or private images from Docker Hub. The discovery of this long-standing vulnerability in a core container registry service aligns with a broader trend of increasing scrutiny on software supply chain security. Recent years have seen numerous high-profile attacks targeting various stages of the software development lifecycle, from compromised open-source libraries to malicious packages in public registries. The industry has been moving towards more robust practices like software bill of materials (SBOMs), image signing, and stricter admission controls in Kubernetes to mitigate these risks. This Docker Hub flaw serves as a stark reminder that even fundamental infrastructure components can harbor critical vulnerabilities that evade detection for extended periods, necessitating a defense-in-depth approach to supply chain security. In practice, this incident reinforces several key actions for practitioners. First, organizations should implement stringent image scanning and vulnerability management processes for all container images, both third-party and internally developed. Second, employing image signing and verification mechanisms (e.g., Notary, Cosign) can help ensure that only trusted and unaltered images are deployed. Third, adopting a least-privilege approach to PATs and API keys, along with regular rotation and auditing, is crucial. Finally, continuous monitoring of container registries for suspicious activity and integrating security checks throughout the CI/CD pipeline are essential to detect and prevent the deployment of compromised images. While Docker has patched the vulnerability and found no evidence of exploitation, the potential impact highlights the need for proactive security measures to protect against such supply chain threats.