Docker Hub Fixes Critical Image Impersonation Flaw

Docker has disclosed and patched CVE-2026-105445, a critical flaw in Docker Hub rated CVSS 9.8 that let any authenticated user push, pull, or delete container images in a completely different user’s repositories. Docker fixed the issue on September 30, 2026. The Hacker News and BleepingComputer reported that the vulnerability had been present in Docker Hub for approximately two years before discovery.

The flaw

Personal access tokens in Docker Hub are meant to give their owner programmatic access to their own repositories. CVE-2026-105445 broke that boundary. A valid PAT could be used to interact with a different account’s repositories entirely, including writing new image tags, pulling private images, and deleting existing ones. Docker Hub handles the PAT authorization check server-side, so there is no self-hosted Docker Registry component involved and no patch that users need to apply themselves.

Docker has not reported confirmed exploitation in the wild, and the CVE does not appear on CISA’s Known Exploited Vulnerabilities catalog.

The exposure window

Docker Hub is the largest public container registry. Millions of base images are pulled from it daily by automated build systems and developers who never think twice about the source. A two-year authentication flaw in that environment is not the same as a two-year authentication flaw in a niche internal tool. An attacker who knew about CVE-2026-105445 could have pushed modified image tags into arbitrary repositories without the owner ever being notified.

The absence of a KEV listing means confirmed active exploitation has not surfaced. It does not mean exploitation did not occur during those two years.

This failure mode has precedent. The CrowdSec source code theft via TanStack and the BigCommerce Ribon app breach both involved trusted intermediaries whose access-control layer was quietly bypassed. The pattern is consistent: the attacker does not break into the victim’s environment directly, they compromise something the victim already trusts.

What to do

Docker has patched the flaw server-side in Docker Hub. Users do not need to upgrade any local tooling. That said:

• Rotate any PATs issued before October 2026 and treat the prior two years as a potential exposure window.
• Audit Docker Hub repository event history for unexpected push, pull, or delete activity on repositories you own.
• Review base images your builds pull from public Docker Hub repositories. Where ownership or provenance is unclear, verify the image digest matches what you expect.

Pinning container image references to a specific SHA256 digest, rather than a mutable tag like latest, limits how much a tampered registry push can affect downstream builds without being noticed. It is not a full defense against a trust compromise, but it makes the tamper visible.

Sources: NVD CVE-2026-105445, The Hacker News, BleepingComputer