Red Hat Quay SSRF via External Reference in Repo Mirror
CVE-2026-15927 Published on July 21, 2026
Quay: mirror-registry: ssrf: repo-level mirror accepts external_reference without url validation
A flaw was found in Red Hat Quay's repository-level mirror configuration
feature. The POST and PUT handlers in endpoints/api/mirror.py accept an
external_reference parameter without SSRF validation, unlike the
organization-level mirror handlers which apply validate_external_registry_url().
A repository administrator can supply a crafted hostname that causes the Quay
mirror worker to make requests via Skopeo to internal network services, cloud
metadata endpoints, or other resources not intended to be reachable from the
Quay application.
Vulnerability Analysis
CVE-2026-15927 can be exploited with network access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Timeline
Reported to Red Hat.
Made public. 153 days later.
Weakness Type
What is a SSRF Vulnerability?
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
CVE-2026-15927 has been classified to as a SSRF vulnerability or weakness.
Products Associated with CVE-2026-15927
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