The vulnerability is a failure to validate the number of grant identifiers requested before allocating them in the Linux kernel’s grant table mechanism. A request whose count exceeds the global grant limit is not rejected until memory is allocated, allowing a user to trigger a large allocation that can exhaust kernel memory or cause a kernel panic. The flaw arises from unchecked input that permits an integer wraparound during the count check, ultimately leading to uncontrolled resource consumption, a classic instance of CWE-770 (Resource Exhaustion). The impact is a denial of service; an attacker can destabilize the kernel by exhausting memory or inducing a fault.

Linux kernel modules that implement grant table allocation are affected. The description does not specify a version range; the flaw exists in the grant table allocation logic as implemented before the fix. All unpatched releases could be impacted, but the specific affected versions are not listed.

The CVSS score of 5.5 and an EPSS score of less than 1% indicate a low likelihood of exploitation. The vulnerability is not listed in the CISA KEV catalog. The likely attack requires access to the Xen grant table ioctl interface, which is generally available to privileged users or within a Xen domain context. Because the flaw allows large allocations, exploitation would succeed in an environment where the vulnerable process runs with sufficient privileges. The absence of exploitation statistics makes the precise likelihood uncertain, but the potential to consume kernel memory suggests a high impact if successful.