Executive brief
Red Hat Quay, a container image registry, contains a security flaw in its notification system. A repository administrator can configure webhooks to send data to internal network addresses or cloud management services that should be private. This could allow an attacker to probe internal infrastructure or access sensitive cloud metadata from within the corporate network.
Technical details
A Server-Side Request Forgery (SSRF) vulnerability exists in Red Hat Quay's notification webhook feature. The SlackMethod and WebhookMethod handlers in 'notifications/notificationmethod.py' fail to implement the 'validate_external_registry_url()' validator used by other Quay components. While a 'HOSTNAME_BLACKLIST' check exists, it only performs exact matching against a minimal list (e.g., localhost), which is easily bypassed using private IP literals or cloud metadata hostnames. An authenticated repository administrator can exploit this to make the Quay worker issue POST requests to internal network addresses or cloud infrastructure endpoints. This enables blind SSRF from the worker's network context.
Affected products
- Red Hat Quay 3 3
- Red Hat OpenShift Update Service 5
Timeline
- 2026-07-24: disclosed: Initial vulnerability report and CVE assignment
- 2026-07-24: advisory: NVD publication date