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CVE-2026-93253

In the Linux kernel, the following vulnerability has been resolved: sched/isolation: Defer freeing of cpumask memblock memory to initcall When testing a linux-next kernel with commit 59bd1d914bb5…

Published Sep 24, 2026EPSS 0.19%

Overview

CVE-2026-93253 is a known-severity vulnerability. It was published on September 24, 2026.

Technical description

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

sched/isolation: Defer freeing of cpumask memblock memory to initcall

When testing a linux-next kernel with commit 59bd1d914bb5 ("memblock:

warn when freeing reserved memory before memory map is initialized"),

the following warning was hit when there was a "nohz_full" kernel boot

parameter.

Cannot free reserved memory because of deferred initialization of the memory map

WARNING: mm/memblock.c:904 at __free_reserved_area+0xde/0xf0, CPU#0: swapper/0/0

:

Call Trace:

<TASK>

memblock_phys_free+0xcb/0x100

housekeeping_init+0x14c/0x170

start_kernel+0x207/0x450

x86_64_start_reservations+0x24/0x30

x86_64_start_kernel+0xda/0xe0

common_startup_64+0x13e/0x141

</TASK>

IOW, we shouldn't free memblock allocated memory so early

in the boot process when memory map isn't fully initialized in

deferred_init_memmap().

Fix it by saving the housekeeping cpumask memblock memory to be

freed into a llist f

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Frequently asked questions

What is CVE-2026-93253?

CVE-2026-93253 is a known-severity vulnerability. It was published on September 24, 2026.

How severe is CVE-2026-93253?

CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.

How do I fix or remediate CVE-2026-93253?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-93253?

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