CVE-2026-99250: Linux kernel · printk: Postpone kthread startup
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in a86bcdd84c8fe7a45f73e12d53fe06fea07d1ceb : update Linux kernel when convenient.
Data as of 3 Nov 2026, 11:43 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in a86bcdd84c8fe7a45f73e12d53fe06fea07d1ceb, 7595bacee48bc30b5021eccf199d704d4e5e5374, 792acd173da0884f0172c68cb473f42cf93c647e +1
Exploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Upgrade Linux kernel to a86bcdd84c8fe7a45f73e12d53fe06fea07d1ceb, 7595bacee48bc30b5021eccf199d704d4e5e5374, 792acd173da0884f0172c68cb473f42cf93c647e or 5f339c46f153184570f16c8e789c9709b14cbe8b.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix has been implemented that postpones the startup of the NBCON console printing kthreads until after all architecture initialization calls have completed. Users should update to the fixed Linux kernel versions containing the relevant commits to resolve this issue.
Description
A Linux kernel vulnerability (CVE-2026-99250) involves early startup of kthreads related to console printing (NBCON) during boot. These kthreads start very early and asynchronously enable/disable interrupts, potentially interfering with SMP setup and causing system hangs on some hardware platforms. The issue is resolved by postponing the kthread startup until after all architecture-specific initialization calls complete.
References
- git.kernel.org/stable/c/a86bcdd84c8fe7a45f73e12d53fe06fea07d1ceb (opens in a new tab)
- git.kernel.org/stable/c/7595bacee48bc30b5021eccf199d704d4e5e5374 (opens in a new tab)
- git.kernel.org/stable/c/792acd173da0884f0172c68cb473f42cf93c647e (opens in a new tab)
- git.kernel.org/stable/c/5f339c46f153184570f16c8e789c9709b14cbe8b (opens in a new tab)