CVE-2026-80727: Linux kernel · x86/mce: Set up the polling timer before CMCI discovery
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 3 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: x86/mce: Set up the polling timer before CMCI discovery I hit the following on one of my machines: mce: CPU0 BANK15 CMCI inherited storm ------------[ cut here ]------------ ODEBUG: assert_init not available (active state 0) object: (____ptrval____) object type: timer_list hint: 0x0 WARNING: lib/debugobjects.c:632 at debug_object_assert_init+0x178/0x230, CPU#0: swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 7.2.0-rc5 #3 PREEMPTLAZY RIP: 0010:debug_object_assert_init+0x18f/0x230 Call Trace: <TASK> __mod_timer mce_timer_kick cmci_discover intel_init_cmci mce_intel_feature_init mcheck_cpu_init identify_cpu identify_boot_cpu arch_cpu_finalize_init start_kernel A second splat follows right after, from timer_setup() finding that same timer already queued: ODEBUG: init active (active state 0) object: (____ptrval____) object type: timer_list hint: stub_timer+0x0/0x10 This is happening because CMCI storm detection is trying to modify the timer before latter was properly set up. Set up the timer first. __mcheck_cpu_setup_timer() only calls timer_setup(), and depends on neither the generic nor the vendor init. [ bp: Massage commit message. ]
References
- ubuntu.com/security/CVE-2026-80727 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80727 (opens in a new tab)
- git.kernel.org/linus/a213dfaa2596c1c0dc4dae91c14fbfa499c03223 (opens in a new tab)
- git.kernel.org/stable/c/17ab68d0cf6a41bff61b1e13c6141d9e463736ae (opens in a new tab)
- git.kernel.org/stable/c/4f4cba3947d2f0eceb32727e198ca2c149a653a9 (opens in a new tab)
- git.kernel.org/stable/c/a213dfaa2596c1c0dc4dae91c14fbfa499c03223 (opens in a new tab)
- git.kernel.org/stable/c/e708fc1566ebd4a2d3f2546e6310d64d362db80d (opens in a new tab)