VulnerabilityPublished 19 Oct 2026Updated 27 Oct 2026

CVE-2026-98841: Linux kernel · virt: vmgenid: set driver_data before registering notification handlers

Affects Linux kernelSource GCVE Database

Authoritative record:CVE-2026-98841· High

Not known to be exploited.

Data as of 28 Oct 2026, 01:28 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected 6.17.0-5.5 – 7.0.0-38.38 23 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1017.17 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1016.16 9 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 13 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected 7.0.0-1002.3 – 7.0.0-1008.9 6 affected builds	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: 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().

References

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