Linux Kernel up to 6.18.54/7.2.8 KVM arm64 SVE pkvm_init_features_from_host null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k1.23-

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.18.54/7.2.8. Impacted is the function pkvm_init_features_from_host of the component KVM arm64 SVE. Performing a manipulation results in null pointer dereference. This vulnerability is reported as CVE-2026-98928. The attack is possible to be carried out remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 6.18.54/7.2.8. This affects the function pkvm_init_features_from_host of the component KVM arm64 SVE. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Derive GUEST_HAS_SVE from the SVE feature bit at EL2 pkvm_init_features_from_host() takes KVM_ARCH_FLAG_GUEST_HAS_SVE and KVM_ARM_VCPU_SVE from the host separately, but pkvm_vcpu_init_sve() tests the bit while vcpu_has_sve() reads the flag. A host that sets the flag without the bit gets a vCPU with a NULL sve_state that the world switch loads the guest's SVE state from. Derive the flag from the bit, and drop the protected path's copy of the host's flag, which is dead code since protected VMs are not allowed SVE.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-98928 since 09/25/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/23/2026).

Upgrading to version 6.18.55 or 7.2.9 eliminates this vulnerability. Applying the patch 4efda204087145d40a84344edec7e9d3885ad3ab/7b5e99d286747b6b5b583b8efcd06bdbdd94b229/4f16c5fc8dc4c5596e3777ab9f449a54e3f85fd5 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

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

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
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
Patch: 4efda204087145d40a84344edec7e9d3885ad3ab/7b5e99d286747b6b5b583b8efcd06bdbdd94b229/4f16c5fc8dc4c5596e3777ab9f449a54e3f85fd5

Timelineinfo

09/25/2026 CVE reserved
10/23/2026 +28 days Advisory disclosed
10/23/2026 +0 days VulDB entry created
10/23/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98928 (🔒)
GCVE (CVE): GCVE-0-2026-98928
GCVE (VulDB): GCVE-100-425727

Entryinfo

Created: 10/23/2026 14:50
Changes: 10/23/2026 14:50 (59)
Complete: 🔍
Cache ID: 216::103

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