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

> Repository administrators can exploit missing URL validation in Quay's mirror configuration to perform Server-Side Request Forgery against internal services.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Jul 2026
- **Updated:** 22 Sep 2026
- **Also known as:** GHSA-9rpm-rwwc-xw43

## What is CVE-2026-15927?

CVE-2026-15927 is a medium-severity server-side request forgery vulnerability in Red Hat Quay 3.10, published on 21 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official 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.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-15927?


## How do I fix CVE-2026-15927?

No fix has been published for CVE-2026-15927 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15927 being exploited?

There is no known exploitation of CVE-2026-15927 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15927 and fix it if it is affected.

What it is: CVE-2026-15927 is a medium-severity server-side request forgery vulnerability in Red Hat Quay 3.10, published on 21 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-15927 in the wild and no public exploit code.

Affected product: Red Hat Quay 3.10. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-15927/ (Markdown: https://insights.sbomify.com/CVE-2026-15927/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15927
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15927
- OSV: https://osv.dev/vulnerability/CVE-2026-15927

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15927/
Summaries are generated and may contain mistakes; the official description above is the record.