# CVE-2026-16254: Quay Claircore denial of service in apk package scanner

Source: https://junglewise.ai/threats/cve-2026-16254-quay-claircore-denial-of-service-in-apk-package-scanner  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-20. Updated: 2026-07-20  
License: CC BY 4.0 with a link back

CVE-2026-16254 · Severity: medium · CVSS 4.3 · Published 2026-07-20

Claircore is a library used by container security tools like Clair and Quay to scan container images for vulnerabilities. A flaw in how it processes Alpine Linux (apk) package databases allows a specially crafted container image to crash the scanning service. This can lead to a denial-of-service, preventing the system from successfully indexing and auditing new container images.

Technologies: [Quay Claircore](https://junglewise.ai/threats/technologies/claircore). Vendors: [Quay](https://junglewise.ai/threats/vendors/quay).

## Quick answers

**Is CVE-2026-16254 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-16254 being exploited in the wild.

**How severe is CVE-2026-16254?** Medium severity, with a CVSS score of 4.3, published 20 July 2026.

**Which products and versions are affected?** Quay Claircore; Red Hat Red Hat Advanced Cluster Security 4.

**Is there a fix for CVE-2026-16254?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-16254 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-16254?** Check whether you run Quay Claircore. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds read vulnerability (CWE-125) exists in the apk package-database parser of Claircore. When the scanner encounters malformed data within a container layer, it triggers a Go panic due to an out-of-bounds slice access. Because this panic is not recovered within the indexing path, it causes the entire Clair indexer process to terminate. An attacker with the ability to submit a crafted container image for indexing can exploit this to cause a denial of service. While the impact may be mitigated by automatic container orchestration restarts (e.g., Kubernetes), it still results in a disruption of the indexing service.

## Affected products

- Quay Claircore
- Red Hat Red Hat Advanced Cluster Security 4

## Timeline

- 2026-07-20: disclosed: Vulnerability reported via Red Hat Bugzilla and NVD.

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-16254](https://access.redhat.com/security/cve/CVE-2026-16254)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2502701](https://bugzilla.redhat.com/show_bug.cgi?id=2502701)

## Related threats

- [Red Hat Clair SSRF in fetcher component](https://junglewise.ai/threats/cve-2026-10517-red-hat-clair-ssrf-in-fetcher-component)