VulnerabilityPublished 18 Oct 2026

CVE-2026-98472: Linux kernel · KVM: SEV: Free have_run_cpus during VM destruction even if VM is no longer SEV

Source GCVE Database

Authoritative record:CVE-2026-98472· Medium

Not known to be exploited · fixed in 9784e5ca91b37b387f3f414af4340c54f7a63566 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9784e5ca91b37b387f3f414af4340c54f7a63566, 12c1f6e03f944e399bd2c88441dca5dc702b95a5, 6aef7cf800098749ff5d660222efaf6e01e98c09

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.

ghsa-qccv-gmm4-2g2g

What to do

Upgrade Linux kernel to 9784e5ca91b37b387f3f414af4340c54f7a63566, 12c1f6e03f944e399bd2c88441dca5dc702b95a5 or 6aef7cf800098749ff5d660222efaf6e01e98c09.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 6f38f8c574642a822f2e85f079fa29a49176c49c, < 9784e5ca91b37b387f3f414af4340c54f7a63566	Fixed in 9784e5ca91b37b387f3f414af4340c54f7a63566
LinuxLinux	Affected ≥ 6f38f8c574642a822f2e85f079fa29a49176c49c, < 12c1f6e03f944e399bd2c88441dca5dc702b95a5	Fixed in 12c1f6e03f944e399bd2c88441dca5dc702b95a5
LinuxLinux	Affected ≥ 6f38f8c574642a822f2e85f079fa29a49176c49c, < 6aef7cf800098749ff5d660222efaf6e01e98c09	Fixed in 6aef7cf800098749ff5d660222efaf6e01e98c09
LinuxLinux	Affected =6.17	Fixed in–
Debiandebian/linux`pkg:deb/debian/linux`Other threats	Affected =6.17	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to unconditionally free the 'have_run_cpus' cpumask during VM destruction, addressing the vulnerability. Users should update to a Linux kernel version that includes this fix. Since this is a kernel-level fix, applying the official kernel update is the recommended remediation.

Description

A vulnerability in the Linux kernel's KVM SEV implementation involves improper freeing of the 'have_run_cpus' cpumask during virtual machine destruction, even if the VM is no longer using SEV. This issue arises because an SEV VM becomes a non-SEV VM if it is intra-host migrated, but the cpumask is still unconditionally freed in the VM destroy path. The flaw could lead to use-after-free conditions if the mask is not properly nullified. The vulnerability has been resolved by ensuring the cpumask is freed unconditionally during VM destruction.

Impact

If unpatched, the improper freeing of the 'have_run_cpus' cpumask could lead to use-after-free conditions within the KVM SEV virtualization code. This could potentially cause kernel memory corruption or instability. However, no known exploits in the wild have been reported for this vulnerability. The impact is limited to environments using KVM with SEV-enabled VMs that undergo intra-host migration.

Summary

The vulnerability in the Linux kernel affects the KVM SEV (Secure Encrypted Virtualization) feature. Specifically, the 'have_run_cpus' cpumask, which tracks CPUs that have run the VM, is freed unconditionally during VM destruction. This is necessary because an SEV VM transitions to a non-SEV VM state upon intra-host migration, but the cpumask could otherwise remain allocated, leading to potential use-after-free (UAF) issues. The patch ensures that the cpumask is freed in the VM destroy path regardless of the VM's SEV state, improving robustness and preventing UAF vulnerabilities related to this resource management.

References

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