PT-2026-61257 · Linux · Linux

CVE-2026-63940 · Published 2026-07-19 · Updated 2026-07-19

Mitre

CVSS v3.1

9.3

Critical

Base vector

AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

In the Linux kernel, the following vulnerability has been resolved:

KVM: SEV: Ignore Port I/O requests of length '0'

Explicitly ignore Port I/O requests of length '0' (or count '0'), so that setting up the software scratch area (and other code) doesn't have to worry about underflowing the length, and to allow for WARNing on trying to configure the scratch area with len==0.

Fix

Related Identifiers

CVE-2026-63940

Affected Products

Linux

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2026-63940 · Security Note
• https://git.kernel.org/stable/c/3b6035bc6bff20e89752ce4358bc4c9a9d5883f2 · Note
• https://git.kernel.org/stable/c/2254972d4d69e279ba4e87bf0968eb08ad0d3c92 · Note
• https://git.kernel.org/stable/c/3988bd2723de407ae90fa7a6f6029b4e60238c58 · Note
• https://git.kernel.org/stable/c/c30cde934c7813b4e3069765dac64ce3d31e34f2 · Note