A critical vulnerability in Red Hat Quay could allow attackers to access private container images and replace content in repositories across an affected registry.
Red Hat Quay is an enterprise container registry used to store, manage and distribute container images. It allows organizations to control who can download or upload images used in application development and deployment.
The vulnerability, tracked as CVE-2026-123710, has a CVSS score of 9.8. It affects deployments where the service responsible for managing signing keys is accessible to untrusted clients.
“This Critical flaw in Red Hat Quay’s service key server allows an unauthenticated attacker to take over registry token signing,” Red Hat said in its advisory.
When anonymous access is enabled, an attacker without an account can obtain a registry token and exploit weaknesses in the key rotation mechanism to install their own trusted signing key.
The attacker can then generate tokens granting read and write access to any repository, bypassing normal access restrictions. This could expose private images and any credentials or other secrets stored in them, while also allowing attackers to overwrite images that other systems subsequently download.
The malicious signing key can be configured without an expiration date and survives registry restarts unless removed.
“Rotation also deletes the legitimate instance key as a side effect, and the attacker key can delete replacement instance keys,” Red Hat’s Bugzilla report explains.
This could interfere with normal registry operations, preventing legitimate users from uploading or downloading images.
“Turning off anonymous access doesn’t protect you, because any valid Quay account can still exploit the flaw,” Red Hat warns in additional guidance.
The company also notes that changing passwords or regenerating robot tokens does not invalidate an unauthorized signing key.
Red Hat recommends restricting access to the key-management service, reviewing logs for suspicious key changes, and removing unauthorized keys. However, the company warns that attackers could reinstall malicious keys until a fix is deployed.
The vulnerability was discovered by Red Hat’s Dave O’Connor.
Neither the advisory nor the Bugzilla report identifies a fixed version. However, fixes for this vulnerability and another Quay flaw tracked as CVE-2026-110697 were merged into the project’s GitHub repository on November 11.
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