Docker Hub Critical Flaw Allowed Token-Based User Impersonation
A critical vulnerability in Docker Hub let attackers impersonate users via personal access tokens during account conversions, though no exploitation was found.
Key points
- CVE-2026-105445 allowed token reassignment without consent or secret rotation.
- Docker deployed a fix on September 30, 2026, after confirming the issue.
- The company found no evidence of exploitation during the exposure window.
Docker disclosed a critical vulnerability, tracked as CVE-2026-105445, in its Docker Hub registry that allowed attackers to impersonate other users. The flaw enabled unauthorized access to container repositories by exploiting how personal access tokens were handled during account conversions.
The vulnerability stemmed from a process change introduced on August 26, 2024, which reassigned personal access tokens to new organization owners without rotating the secret or obtaining consent. This allowed attackers to use existing tokens to authenticate as target users, potentially pulling, pushing, or deleting images within the scope of the token’s permissions.
Technical Context and Timeline
According to a security bulletin from the Docker team, the flaw occurred when a personal account was converted into an organization. The system transferred the original account’s personal access tokens to the designated owner without changing the token secret. Attackers could create an account, generate a token, and then convert it into an organization while naming a victim as the owner.
This mechanism allowed the attacker to retain knowledge of the token secret while Docker Hub linked that token to the victim’s identity. Registry requests using the token authenticated as the target user. Because this allowed publishing images under legitimate names, Docker treated the issue as a software supply chain risk and rated it critical.
The exposure window lasted from August 26, 2024, at 20:33 UTC until September 30, 2026, at approximately 19:10 UTC. On September 30, 2026, Docker received a report describing the issue, confirmed it, and deployed a fix to production less than four hours later.
Impact and Mitigation
Docker stated that the vulnerability did not provide access to the Docker Hub web interface. Attackers could not use the flaw to change passwords, email addresses, or two-factor authentication settings, which prevented full account takeover or locking out legitimate users. The impact was limited to registry-level actions such as pulling, pushing, or deleting images in repositories where the target had access.
Docker examined 304,000 pushes made with transferred tokens and analyzed high-risk public images. The company reported finding no evidence of exploitation during the investigation. Affected users and organization owners were notified on October 2, 2026, and transferred personal access tokens were deactivated on October 8, except for those whose owners explicitly requested to retain them.
What should you do?
Security teams should review their container image sources for any unexpected changes or unauthorized pushes during the exposure window. Organizations should audit their personal access tokens to ensure they are still valid and have not been inadvertently shared or transferred.
What to do and how to stay safe: Docker
- Audit personal access tokens to ensure they have not been transferred or shared without authorization.
- Review container image logs for any unexpected pushes or deletions between August 2024 and September 2026.
- Rotate all personal access tokens immediately to invalidate any potentially compromised credentials.
- Monitor Docker Hub announcements for further updates on this vulnerability and related security advisories.
Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger
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 CVE-2026-105445?
It is a critical vulnerability in Docker Hub that allowed attackers to impersonate users by exploiting personal access token reassignment during account conversions.
Did attackers exploit this vulnerability?
No, Docker found no evidence of exploitation after examining 304,000 pushes and analyzing high-risk public images.
When was the fix deployed?
Docker deployed a fix to production on September 30, 2026, less than four hours after confirming the issue.
