PatchSiren cyber security CVE debrief
CVE-2026-15927 Red Hat CVE debrief
The Red Hat Quay repository-level mirror configuration feature contains a flaw in its POST and PUT handlers, accepting an external_reference parameter without SSRF validation. This allows a repository administrator to supply a crafted hostname, potentially causing the Quay mirror worker to make requests to internal network services or cloud metadata endpoints. The vulnerability impacts Quay deployments with repository-level access, allowing potential SSRF attacks on internal services. Affected teams must verify and apply Red Hat's official patches or workarounds, restrict access to Quay's API endpoints, and monitor Quay logs for suspicious activity indicative of SSRF attempts. Additionally, security teams should implement additional security controls, such as validating external registry URLs, to prevent potential SSRF attacks. This vulnerability requires prompt attention to prevent potential SSRF attacks on internal network services or cloud metadata endpoints. Security teams should review compensating controls for exposed systems while remediation is scheduled and verified, and track exceptions, retest remediated assets, and close the item only after evidence is documented.
- Vendor
- Red Hat
- Product
- Red Hat Quay 3.9
- CVSS
- MEDIUM 6.8
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-21
- Original CVE updated
- 2026-08-05
- Advisory published
- 2026-07-21
- Advisory updated
- 2026-08-05
Who should care
Red Hat Quay administrators, users with repository-level access, and security teams responsible for monitoring and protecting against SSRF attacks should be aware of this vulnerability. Affected teams must verify and apply Red Hat's official patches or workarounds, restrict access to Quay's API endpoints, and monitor Quay logs for suspicious activity indicative of SSRF attempts. Additionally, security teams should implement additional security controls, such as validating external registry URLs, to prevent potential SSRF attacks. This vulnerability requires prompt attention to prevent potential SSRF attacks on internal network services or cloud metadata endpoints. Security teams should review compensating controls for exposed systems while remediation is scheduled and verified, and track exceptions, retest remediated assets, and close the item only after evidence is documented. Security teams and Quay administrators must collaborate to assess affected scope, apply mitigations, and verify patch effectiveness. Vulnerability management teams should prioritize patching based on asset inventory and exposure risk. Monitoring and detection teams should be prepared to identify potential SSRF attempts and have incident response plans in place. Asset inventory management is crucial to identify potentially affected systems and prioritize remediation efforts. Red Hat Quay users with repository-level access must be aware of the potential risks and take necessary precautions to protect against SSRF attacks. Security teams should also review relevant monitoring, detection, and logs for exposed assets that need extra review. The vulnerability's impact on the organization depends on the specific Quay configurations and the exposure of internal network services or cloud metadata endpoints. Therefore, a thorough review of the vulnerability's impact and implementation of compensating controls is essential to prevent potential SSRF attacks. Security teams should also consider implementing additional security controls, such as validating external registry URLs, to prevent potential SSRF attacks. The affected product or component is Red Hat Quay, and the vulnerability class is SSRF. A
Technical summary
The Red Hat Quay repository-level mirror configuration feature contains a flaw in its POST and PUT handlers, accepting an external_reference parameter without SSRF validation. This allows a repository administrator to supply a crafted hostname, potentially causing the Quay mirror worker to make requests to internal network services or cloud metadata endpoints. The vulnerability impacts Quay deployments with repository-level access, allowing potential SSRF attacks on internal services.
Defensive priority
Medium-priority vulnerability in Red Hat Quay's repository-level mirror configuration feature, requiring prompt attention to prevent potential SSRF attacks.
Recommended defensive actions
- Verify and apply Red Hat's official patches or workarounds for Quay's mirror configuration feature
- Restrict access to Quay's API endpoints to prevent unauthorized requests
- Monitor Quay logs for suspicious activity indicative of SSRF attempts
- Implement additional security controls, such as validating external registry URLs
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
Evidence notes
Evidence from Red Hat's security advisories and bugzilla reports indicate a flaw in Quay's mirror configuration feature, allowing potential SSRF attacks. However, details are limited, and further verification is required to fully understand the vulnerability's impact. The vulnerability affects Red Hat Quay's repository-level mirror configuration feature, which did not properly validate external references, potentially allowing SSRF attacks. To verify, defenders should review Red Hat's official advisories, inspect Quay configurations for exposed endpoints, and monitor for suspicious activity.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-21T06:16:28.603Z and has not been modified since then.