Red Hat Quay EUVD-2026-58819

Exploitation requires the attacker to hold repository administrator privileges on at least one repository within the target Quay instance (PR:L per CVSS). The attacker must additionally know or successfully enumerate the UUID of a notification belonging to a different repository (AC:H per CVSS - the primary technical barrier). No non-default configuration is required: Quay's notification feature is standard functionality enabled by default when integrations are configured. Exploitation is bounded by: (1) authenticated access as a repository admin is mandatory - unauthenticated external attackers are excluded; (2) the cross-repository UUID must be discovered via guessing, log/UI leakage, or a secondary information source; and (3) the flaw affects notification read and test-trigger operations only - it does not grant write access to repository content or images.

The CVSS 3.1 vector (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N) accurately frames the trade-offs: the vulnerability is network-reachable and requires only low-privilege access (any repository admin), but attack complexity is High because the attacker must successfully obtain or guess a valid notification UUID belonging to a different repository. The Confidentiality impact is High given that webhook signing secrets, Slack API tokens, and email addresses constitute sensitive credentials that can unlock downstream systems. No EPSS probability was provided in the source data, and this CVE does not appear in the CISA KEV catalog, indicating no confirmed widespread active exploitation. POC availability is unknown. In practical terms, the risk is most acute for multi-tenant Quay deployments where mutually untrusting teams share the same instance - even a mid-sized organization running Quay internally should treat secret rotation as an urgent compensating control until a patch is applied. The UUID guessing constraint (AC:H) is a meaningful but imperfect barrier: if UUIDs are sequentially assigned or low-entropy, enumeration becomes feasible; if they are version-4 random UUIDs, brute-force is computationally impractical and the realistic threat actor is an insider or someone who obtained a UUID via a secondary leak.

An authenticated Quay repository administrator calls the notification configuration API endpoint, substituting a guessed or previously leaked UUID belonging to a notification in a different team's repository. The API returns the full notification configuration, exposing a Slack bot token or CI/CD webhook URL with embedded credentials. The attacker reuses these secrets to exfiltrate data from the downstream Slack workspace or trigger unauthorized actions in the CI/CD pipeline. No public POC has been identified, but the exploit requires only standard HTTP API calls with a valid session token.