The kernel bypasses a required security check when handling memory donated to the Ultravisor. The missing PG_arch_1 bit causes exported pages to be considered ready, leading the export routine to finish immediately. Because the page is not truly exported, subsequent secure storage accesses raise exceptions that cannot be resolved, creating an infinite loop. This flaw falls under CWE‑125 and CWE‑248 and can result in a denial of service by freezing the kernel or causing repeated panic loops.

The vulnerability is present in any Linux kernel that aligns with the listed CPEs: the generic Linux kernel, all releases from 5.7 onward, and the 7.0 release candidates 1 through 7. This covers a wide range of production systems that use the s390 architecture as well as developers working with the 7.0 rc series.

The CVSS base score of 7.1 indicates a moderate‑to‑severe impact, while an EPSS score of less than 1% suggests that exploitation is currently unlikely but not impossible. The flaw is not included in the CISA KEV list. An attacker would need kernel‑level privilege or a malicious kernel module that triggers the secure storage path on donated pages; no user‑level input can trigger it. Because the failure manifests within the kernel, patching the kernel is the only definitive fix.