CVE intelligence

CVE-2026-64244

Vulnerability intelligence

Published Jul 24, 2026Sources checked Oct 28, 2026

5.5MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-64244 and is rated Medium severity with a CVSS score of 5.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Aug 14, 2026

CBL-Mariner Releases

Vendor-listed releases

6.6.150.1-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.1%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-64244?

In the Linux kernel, the following vulnerability has been resolved:

drivers/base/memory: set mem->altmap after successful device registration

If __add_memory_block() fails at xa_store() (under memory pressure for example), device_unregister() is called, which eventually triggers memory_block_release() with mem->altmap still set, causing a WARN_ON(mem->altmap). This was triggered by modifying virtio-mem driver.

Fix this by delaying the assignment of mem->altmap until after __add_memory_block() has succeeded.

Source: NVD