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Vulnerabilities

Vulnerability · CVE-2026-98841

In the Linux kernel, the following vulnerability has been resolved: virt: vmgenid: set driver_data before registering notification handlers Both probe paths register their notifica

Published Oct 19, 2026 · catalog updated Oct 20, 2026 · In the Linux kernel,

Open the advisory

Exploitation likelihood is not on this record for CVE-2026-98841. A missing EPSS score is not a low risk. Compare In the Linux kernel, with the linked advisory before you change production.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (In the Linux kernel,).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
  • EPSS is missing. A missing score is not a low risk.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
Awaiting synchronization with FIRST
Remediation
Advisory link
Affected products
Ubuntu:16.04:LTS linux-hwe-edge · Ubuntu:18.04:LTS linux-aws-5.0 · Ubuntu:18.04:LTS linux-aws-5.3 · Ubuntu:18.04:LTS linux-azure · Ubuntu:18.04:LTS linux-azure-5.3 · Ubuntu:18.04:LTS linux-azure-edge

In the Linux kernel, the following vulnerability has been resolved: virt: vmgenid: set driver_data before registering notification handlers Both probe paths register their notification handler before assigning driver_data, which the handler dereferences. In the devicetree path, the notification IRQ can fire as soon as devm_request_irq() registers the handler: the interrupt may already be pending at probe time, for example when a VMM injects the generation-changed notification while restoring a guest from a snapshot that was taken before the driver had probed (Firecracker does exactly this on snapshot restore). The IRQ is also requested with IRQF_SHARED, so another device sharing the line can trigger the handler just as early. The handler then calls vmgenid_notify(), which dereferences the still-NULL driver_data and panics: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.18.38+ #1 PREEMPT(none) Hardware name: linux,dummy-virt (DT) pc : vmgenid_notify.isra.0+0x24/0x8c lr : vmgenid_of_irq_handler+0x14/0x34 Call trace: vmgenid_notify.isra.0+0x24/0x8c (P) vmgenid_of_irq_handler+0x14/0x34 __handle_irq_event_percpu+0x44/0x1bc handle_irq_event+0x4c/0xb4 handle_fasteoi_irq+0xf8/0x1f8 The ACPI path has the same ordering problem: the handler is installed with acpi_install_notify_handler() before driver_data is assigned. ACPI notifications are dispatched asynchronously from a workqueue, so the window is narrow, but a notification arriving between the two calls hits the same NULL dereference. Assign driver_data before registering the handlers. The state is fully initialized at that point, so the handlers are safe to run. Should registration fail, the probe error path leaves no dangling pointer behind: the driver core clears driver_data in device_unbind_cleanup().

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Ubuntu:16.04:LTS linux-hwe-edge4.8.0-28.30~16.04.1, 4.8.0-30.32~16.04.1, 4.8.0-32.34~16.04.1
  • Ubuntu:18.04:LTS linux-aws-5.05.0.0-1021.24~18.04.1, 5.0.0-1022.25~18.04.1, 5.0.0-1023.26~18.04.1
  • Ubuntu:18.04:LTS linux-aws-5.35.3.0-1016.17~18.04.1, 5.3.0-1017.18~18.04.1, 5.3.0-1019.21~18.04.1
  • Ubuntu:18.04:LTS linux-azure4.15.0-1002.2, 4.15.0-1003.3, 4.15.0-1004.4
  • Ubuntu:18.04:LTS linux-azure-5.35.3.0-1007.8~18.04.1, 5.3.0-1008.9~18.04.1, 5.3.0-1009.10~18.04.1
  • Ubuntu:18.04:LTS linux-azure-edge4.18.0-1006.6~18.04.1, 4.18.0-1007.7~18.04.1, 4.18.0-1008.8~18.04.1
  • Ubuntu:18.04:LTS linux-gcp4.15.0-1001.1, 4.15.0-1003.3, 4.15.0-1005.5
  • Ubuntu:18.04:LTS linux-gcp-5.35.3.0-1008.9~18.04.1, 5.3.0-1009.10~18.04.1, 5.3.0-1010.11~18.04.1
  • Ubuntu:18.04:LTS linux-gke-4.154.15.0-1030.32, 4.15.0-1032.34, 4.15.0-1033.35
  • Ubuntu:18.04:LTS linux-gke-5.45.4.0-1025.25~18.04.1, 5.4.0-1027.28~18.04.1, 5.4.0-1029.31~18.04.1
  • Ubuntu:18.04:LTS linux-gkeop-5.45.4.0-1001.1, 5.4.0-1003.3, 5.4.0-1004.5
  • Ubuntu:18.04:LTS linux-hwe4.18.0-13.14~18.04.1, 4.18.0-14.15~18.04.1, 4.18.0-15.16~18.04.1

How to fix CVE-2026-98841

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

Exploitation likelihood is not on this record for CVE-2026-98841. A missing EPSS score is not a low risk. Compare In the Linux kernel, with the linked advisory before you change production.

Which versions are affected?

Compare what you have installed with 4.8.0-28.30~16.04.1, 4.8.0-30.32~16.04.1, 4.8.0-32.34~16.04.1, 5.0.0-1021.24~18.04.1, 5.0.0-1022.25~18.04.1, 5.0.0-1023.26~18.04.1, 5.3.0-1016.17~18.04.1, 5.3.0-1017.18~18.04.1, 5.3.0-1019.21~18.04.1, 4.15.0-1002.2, 4.15.0-1003.3, 4.15.0-1004.4, 5.3.0-1007.8~18.04.1, 5.3.0-1008.9~18.04.1, 5.3.0-1009.10~18.04.1, 4.18.0-1006.6~18.04.1, 4.18.0-1007.7~18.04.1, 4.18.0-1008.8~18.04.1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS is not on this record yet. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Ubuntu security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 19, 2026 · OpenSSF OSV / OSV Scanner

    Detected

    In the Linux kernel, the following vulnerability has been resolved: virt: vmgenid: set driver_data before registering notification handlers Both probe paths register their notification handler before assigning driver_data, which the handler dereferences. In the devicetree path, the notification IRQ can fire as soon as devm_request_irq() registers the handler: the interrupt may already be pending a

  2. Oct 20, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    In the Linux kernel, the following vulnerability has been resolved: virt: vmgenid: set driver_data before registering notification handlers Both probe paths register their notification handler before assigning driver_data, which the handler dereferences. In the devicetree path, the notification IRQ can fire as soon as devm_request_irq() registers the handler: the interrupt may already be pending a

Sources

References

Freshness

Last verified in this catalog Oct 20, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.