Linux Kernel up to 6.18.54/7.2.8/7.3-rc4 SEV sev_migrate_from use after free

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.91

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.18.54/7.2.8/7.3-rc4. The impacted element is the function sev_migrate_from of the component SEV. This manipulation causes use after free. This vulnerability appears as CVE-2026-98472. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.54/7.2.8/7.3-rc4. It has been declared as very critical. Affected by this vulnerability is the function sev_migrate_from of the component SEV. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Free have_run_cpus during VM destruction even if VM is no longer SEV Unconditionally free SEV's "have run CPUs" cpumask in the VM destroy path, i.e. even for what appear to be non-SEV VMs, as an SEV VM becomes a non-SEV VM if its state is intra-host migrated. Alternatively, the mask could be freed in sev_migrate_from() when "converting" the source VM, but that gets annoying because ideally KVM would nullify the mask to guard against UAF, and nullifying the mask would need be conditioned on CPUMASK_OFFSTACK=y. Freeing the mask during sev_migrate_from() is also not robust against other KVM bugs, though that's kind of a moot point since any such bugs would show up even if sev->active is never set. I.e. KVM must get that side of things correct. But, that's not a great reason to add more code just to make things marginally less robust.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-98472 since 09/25/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/18/2026).

Upgrading to version 6.18.55, 7.2.9 or 7.3-rc5 eliminates this vulnerability. Applying the patch 6aef7cf800098749ff5d660222efaf6e01e98c09/9784e5ca91b37b387f3f414af4340c54f7a63566/12c1f6e03f944e399bd2c88441dca5dc702b95a5 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.55/7.2.9/7.3-rc5
Patch: 6aef7cf800098749ff5d660222efaf6e01e98c09/9784e5ca91b37b387f3f414af4340c54f7a63566/12c1f6e03f944e399bd2c88441dca5dc702b95a5

Timelineinfo

09/25/2026 CVE reserved
10/18/2026 +23 days Advisory disclosed
10/18/2026 +0 days VulDB entry created
10/18/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98472 (🔒)
GCVE (CVE): GCVE-0-2026-98472
GCVE (VulDB): GCVE-100-422143

Entryinfo

Created: 10/18/2026 20:39
Changes: 10/18/2026 20:39 (59)
Complete: 🔍
Cache ID: 216::103

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