CVE-2026-63940 PUBLISHED

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

Assigner: Linux
Reserved: 19.07.2026 Published: 19.07.2026 Updated: 20.07.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS Score: 9.3

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 291bd20d5d88814a73d43b55b9428feab2f28094 to 3b6035bc6bff20e89752ce4358bc4c9a9d5883f2 (excl.)
  • affected from 291bd20d5d88814a73d43b55b9428feab2f28094 to 2254972d4d69e279ba4e87bf0968eb08ad0d3c92 (excl.)
  • affected from 291bd20d5d88814a73d43b55b9428feab2f28094 to c30cde934c7813b4e3069765dac64ce3d31e34f2 (excl.)
  • affected from 291bd20d5d88814a73d43b55b9428feab2f28094 to 3988bd2723de407ae90fa7a6f6029b4e60238c58 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.11 is affected
  • unaffected from 0 to 5.11 (excl.)
  • unaffected from 6.12.95 to 6.12.* (incl.)
  • unaffected from 6.18.35 to 6.18.* (incl.)
  • unaffected from 7.0.12 to 7.0.* (incl.)
  • unaffected from 7.1 to * (incl.)

References