CVE-2026-98638: Linux kernel · KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
Rated Medium by Threat Radar's AI analysis · 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 faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc, bae3e4493046de4fefa15f809d9b8dc114e84a3d, 2a2eb10795a1e495aebc7f829ccecb72c05b4fd9
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.
What to do
Upgrade Linux kernel to faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc, bae3e4493046de4fefa15f809d9b8dc114e84a3d or 2a2eb10795a1e495aebc7f829ccecb72c05b4fd9.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available in the Linux kernel as indicated by the fixed commit versions. Users should update to a patched kernel version containing the commits faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc, bae3e4493046de4fefa15f809d9b8dc114e84a3d, or 2a2eb10795a1e495aebc7f829ccecb72c05b4fd9 to remediate this issue.
Description
A vulnerability in the Linux kernel's KVM arm64 code allows an invalid SVE vector length to reach a fatal condition at EL2 due to insufficient validation in pkvm_vcpu_init_sve(). This issue has been fixed by adding proper validation of the vector length before calculating the state size.