CVE-2026-98638
Microsoft — KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()
Microsoft · Not classified by connected sources
EVRS 0 of 100 Informational
Monitor
Rank 2,924 of 2,960 tracked
Why it scores 0
Evidence available: 2 of 8 signalsNo strong exploitation, disclosure, or severity signal is available for this CVE yet.
- CISA KEVDid not apply
- RansomwareNo data
- Vendor exploitationNo data
- EPSSDid not apply
- Microsoft Exploitability IndexNo data
- Pre-patch disclosureNo data
- KEV recencyNo data
- CVSSNo data
The band answers “how soon”, not “how bad”. No data for: Ransomware, Vendor exploitation, Microsoft Exploitability Index, Pre-patch disclosure, KEV recency, CVSS. Why some signals show no data
Fix
No fixed version identified yetAffected versions
Not identified by the connected sources
Remediation
NVD lists one or more references for this CVE that aren't tagged as a patch or vendor advisory. Review them directly to confirm patch availability and applicability before making a remediation decision.
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | Not publishedNVD and the CVE record were checked and hold no score. | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.002 (5.5th pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Not confirmed | Patch Tuesday |
| Public exploit moduleA module existing is not the same as active exploitation. | None known | Metasploit |
| EUVD cross-referenceENISA's record: CVSS 0.0, assigned by Linux. | Listed | ENISA EUVD |
Description
NVDIn the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve() pkvm_vcpu_init_sve() clamps only the upper bound of the host-provided sve_max_vl, so an invalid vector length reaches sve_state_size_from_vl() and the WARN_ON() there, which is fatal at EL2. The existing !sve_state_size test rejects such a length, but only after the macro has run. Check sve_vl_valid() before deriving the state size. A valid length cannot yield a zero size, so the !sve_state_size test goes with it.