SB20261022224 - Improper input validation in Linux kernel hyp nvhe
Published: October 22, 2026
Security Bulletin ID
SB20261022224
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper input validation (CVE-ID: CVE-2026-98638)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service in the arm64 KVM hypervisor.
The vulnerability exists due to improper validation of the host-provided SVE vector length in pkvm_vcpu_init_sve() when initializing virtual CPU SVE state. A local user can cause an invalid vector length to reach sve_state_size_from_vl(), triggering a WARN_ON() that is fatal at EL2 and causing a denial of service.
Remediation
Install update from vendor's website.