CVE-2026-99250
printk: Postpone kthread startup
Description
In the Linux kernel, the following vulnerability has been resolved: printk: Postpone kthread startup There have been various bug reports related to SMP systems hanging on boot. The reports vary but seem to have some overlap with regard to missed IPI's during SMP setup. The reports also show that reverting NBCON console usage allows the bugs to disappear. The NBCON kthreads for console printing are started very early during boot using early_initcall(). Since these kthreads are asynchronously enabling/disabling interrupts during early boot, they may be interfering with early SMP setup on some hardware platforms. Starting the console printing kthreads later has shown to avoid the hanging on systems that could previously reproduce the issue. Postpone kthread starting until after all arch initcalls have completed.
INFO
Published Date :
Nov. 3, 2026, 12:17 p.m.
Last Modified :
Nov. 3, 2026, 12:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-99250
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel to include the postponed kthread startup fix.
- Ensure console printing kthreads start after all arch initcalls.
- Test for system hangs during boot on SMP systems.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-99250.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-99250 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-99250
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-99250 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-99250 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Nov. 03, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: printk: Postpone kthread startup There have been various bug reports related to SMP systems hanging on boot. The reports vary but seem to have some overlap with regard to missed IPI's during SMP setup. The reports also show that reverting NBCON console usage allows the bugs to disappear. The NBCON kthreads for console printing are started very early during boot using early_initcall(). Since these kthreads are asynchronously enabling/disabling interrupts during early boot, they may be interfering with early SMP setup on some hardware platforms. Starting the console printing kthreads later has shown to avoid the hanging on systems that could previously reproduce the issue. Postpone kthread starting until after all arch initcalls have completed. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/99xxx/CVE-2026-99250.json">CVE-2026-99250</a> Added Reference https://git.kernel.org/stable/c/5f339c46f153184570f16c8e789c9709b14cbe8b Added Reference https://git.kernel.org/stable/c/7595bacee48bc30b5021eccf199d704d4e5e5374 Added Reference https://git.kernel.org/stable/c/792acd173da0884f0172c68cb473f42cf93c647e Added Reference https://git.kernel.org/stable/c/a86bcdd84c8fe7a45f73e12d53fe06fea07d1ceb