Is CVE-2026-99250 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-99250 being exploited in the wild.

How severe is CVE-2026-99250?

Informational severity, published 3 November 2026.

Which products and versions are affected?

Linux kernel affected versions prior to fix commit 5f339c46f153184570f16c8e789c9709b14cbe8b.

Is there a fix for CVE-2026-99250?

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-2026-99250 attacked?

It is attacked with local access, in an operating system.

Am I affected by CVE-2026-99250?

Check whether you run Linux kernel at an affected version. 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.

CVE-2026-99250: Linux kernel printk kthread boot hang in SMP systems

CVE-2026-99250 · Severity: info · Published 2026-11-03

The Linux kernel's printk console printing system was starting kthreads too early during boot on multi-processor systems, causing the system to hang. NBCON kthreads were interfering with CPU initialization by asynchronously controlling interrupts. By deferring kthread startup to later in the boot process, the hang is resolved.

Technologies: Linux kernel.

Quick answers

Is CVE-2026-99250 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-99250 being exploited in the wild.
How severe is CVE-2026-99250?: Informational severity, published 3 November 2026.
Which products and versions are affected?: Linux kernel affected versions prior to fix commit 5f339c46f153184570f16c8e789c9709b14cbe8b.
Is there a fix for CVE-2026-99250?: 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-2026-99250 attacked?: It is attacked with local access, in an operating system.
Am I affected by CVE-2026-99250?: Check whether you run Linux kernel at an affected version. 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

NBCON console kthreads were launched via early_initcall() during SMP setup, interfering with inter-processor interrupt (IPI) handling on some hardware platforms. The fix moves the kthread startup to subsys_initcall(), delaying initialization until after architecture-specific initcalls complete. This resolves reported SMP boot hangs on affected systems.

Affected products

Linux Kernel affected versions prior to fix commit 5f339c46f153184570f16c8e789c9709b14cbe8b

Timeline

2026-10-16: other: Fix commit 5f339c46f153184570f16c8e789c9709b14cbe8b authored
2026-11-03: disclosed

References

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