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8.9

CVE-2026-63940: Linux kernel KVM could mishandle zero-length I/O

CVE-2026-63940 · published 3 months ago
Summary

The KVM component of the Linux kernel could treat a request with a length of zero as valid, which might cause unexpected behavior when setting up certain memory areas. This affects Canonical’s Linux kernel packages for HWE Edge, AWS (5.0 and 5.3), and Azure (including 5.3). Install the latest kernel updates from your vendor to apply the fix.

What to do
  • Update canonical linux-hwe-7.0 to version 7.0.0-28.28~24.04.1.
  • Update canonical linux-nvidia-7.0 to version 7.0.0-1016.16~24.04.1.
  • Update canonical linux to version 7.0.0-28.28.
  • Update canonical linux-aws to version 7.0.0-1009.9.
  • Update canonical linux-azure to version 7.0.0-1010.10.
  • Update canonical linux-azure-fde to version 7.0.0-1009.9.
  • Update canonical linux-gcp to version 7.0.0-1008.8.
  • Update canonical linux-gke to version 7.0.0-1003.4.
  • Update canonical linux-ibm to version 7.0.0-1010.10.
  • Update canonical linux-nvidia to version 7.0.0-1016.16.
  • Update canonical linux-nvidia-bos to version 7.0.0-2016.16.
  • Update canonical linux-oem-7.0 to version 7.0.0-1009.9.
  • Update canonical linux-oracle to version 7.0.0-1008.8.
  • Update canonical linux-raspi to version 7.0.0-1015.15.
  • Update canonical linux-realtime to version 7.0.0-28.28.1.
  • Update canonical linux-riscv to version 7.0.0-28.28.1.
  • Update canonical linux-riscv-7.0 to version 7.0.0-28.28.1~24.04.3.
  • Update debian rootio-linux to version 6.1.177-1.root.io.161.
  • Update debian linux to version 6.12.95-1.
  • Update debian linux to version 7.0.12-1.
  • Update canonical linux-azure-7.0 to version 7.0.0-1014.14~24.04.1.
  • Update canonical linux-gcp-7.0 to version 7.0.0-1011.11~24.04.1.
  • Update canonical linux-nvidia-tegra to version 6.8.0-1035.38.
  • Update canonical linux-oracle-7.0 to version 7.0.0-1011.11~24.04.1.
  • Update linux to version 5.15.0-198.208.aikido.116.
  • Update rootio-linux to version 5.15.0-198.208.aikido.116.
  • Update linux kernel to version 7.0.12.
  • Update linux to version 6.1.190-1.aikido.167.
  • Update rootio-linux to version 6.1.190-1.aikido.167.
  • Update canonical linux to version 6.8.0-147.147.
  • Update canonical linux-aws to version 6.8.0-1067.70.
  • Update canonical linux-azure to version 6.8.0-1071.79.
  • Update canonical linux-azure-fde to version 6.8.0-1069.76.
  • Update canonical linux-azure-fde-7.0 to version 7.0.0-1013.13~24.04.1.
  • Update canonical linux-gcp to version 6.8.0-1071.79.
  • Update canonical linux-gke to version 6.8.0-1066.74.
  • Update canonical linux-gkeop to version 6.8.0-1052.56.
  • Update canonical linux-ibm to version 6.8.0-1067.68.
  • Update canonical linux-lowlatency to version 6.8.0-147.147.1.
  • Update canonical linux-oracle to version 6.8.0-1064.67.
  • Update canonical linux-bluefield to version 6.8.0-1033.38.
  • Update canonical linux-realtime to version 6.8.1-1062.63.
  • Update canonical linux-aws-fips to version 6.8.0-1067.70+fips1.
  • Update canonical linux-azure-fips to version 6.8.0-1071.79+fips1.
  • Update canonical linux-fips to version 6.8.0-147.147+fips1.
  • Update canonical linux-gcp-fips to version 6.8.0-1071.79+fips1.
  • Update linux to version 5.15.0-202.212.aikido.118.
  • Update rootio-linux to version 5.15.0-202.212.aikido.118.
  • Update bellsoft linux-lts to version 6.1.191-r0.
  • Update bellsoft linux-lts to version 6.12.95-r0.
  • Update bellsoft linux-lts to version 6.18.35-r1.
  • Update linux linux to version 3b6035bc6bff20e89752ce4358bc4c9a9d5883f2 or later.
Affected software
Ecosystem VendorProductAffected versions
Ubuntu:16.04:LTS canonical linux-hwe-edge All versions
Ubuntu:18.04:LTS canonical linux-aws-5.0 All versions
Ubuntu:18.04:LTS canonical linux-aws-5.3 All versions
Ubuntu:18.04:LTS canonical linux-azure All versions
Ubuntu:18.04:LTS canonical linux-azure-5.3 All versions
Ubuntu:18.04:LTS canonical linux-azure-edge All versions
Ubuntu:18.04:LTS canonical linux-gcp All versions
Ubuntu:18.04:LTS canonical linux-gcp-5.3 All versions
Ubuntu:18.04:LTS canonical linux-gke-4.15 All versions
Ubuntu:18.04:LTS canonical linux-gke-5.4 All versions
Ubuntu:18.04:LTS canonical linux-gkeop-5.4 All versions
Ubuntu:18.04:LTS canonical linux-hwe All versions
Ubuntu:18.04:LTS canonical linux-hwe-edge All versions
Ubuntu:18.04:LTS canonical linux-oem All versions
Ubuntu:18.04:LTS canonical linux-oracle-5.0 All versions
Ubuntu:18.04:LTS canonical linux-oracle-5.3 All versions
Ubuntu:20.04:LTS canonical linux-aws-5.11 All versions
Ubuntu:20.04:LTS canonical linux-aws-5.13 All versions
Ubuntu:Pro:20.04:LTS canonical linux-aws-5.15 All versions
Ubuntu:20.04:LTS canonical linux-aws-5.8 All versions
Ubuntu:20.04:LTS canonical linux-azure-5.11 All versions
Ubuntu:20.04:LTS canonical linux-azure-5.13 All versions
Ubuntu:Pro:20.04:LTS canonical linux-azure-5.15 All versions
Ubuntu:20.04:LTS canonical linux-azure-5.8 All versions
Ubuntu:20.04:LTS canonical linux-azure-fde All versions
Ubuntu:Pro:20.04:LTS canonical linux-azure-fde-5.15 All versions
Ubuntu:20.04:LTS canonical linux-gcp-5.11 All versions
Ubuntu:20.04:LTS canonical linux-gcp-5.13 All versions
Ubuntu:Pro:20.04:LTS canonical linux-gcp-5.15 All versions
Ubuntu:20.04:LTS canonical linux-gcp-5.8 All versions
Ubuntu:20.04:LTS canonical linux-gke All versions
Ubuntu:20.04:LTS canonical linux-gke-5.15 All versions
Ubuntu:20.04:LTS canonical linux-gkeop All versions
Ubuntu:20.04:LTS canonical linux-gkeop-5.15 All versions
Ubuntu:20.04:LTS canonical linux-hwe-5.11 All versions
Ubuntu:20.04:LTS canonical linux-hwe-5.13 All versions
Ubuntu:Pro:20.04:LTS canonical linux-hwe-5.15 All versions
Ubuntu:20.04:LTS canonical linux-hwe-5.8 All versions
Ubuntu:Pro:20.04:LTS canonical linux-ibm-5.15 All versions
Ubuntu:20.04:LTS canonical linux-intel-5.13 All versions
Ubuntu:Pro:20.04:LTS canonical linux-intel-iotg-5.15 All versions
Ubuntu:Pro:20.04:LTS canonical linux-lowlatency-hwe-5.15 All versions
Ubuntu:Pro:20.04:LTS canonical linux-nvidia-tegra-5.15 All versions
Ubuntu:20.04:LTS canonical linux-oem-5.10 All versions
Ubuntu:20.04:LTS canonical linux-oem-5.13 All versions
Ubuntu:20.04:LTS canonical linux-oem-5.14 All versions
Ubuntu:20.04:LTS canonical linux-oem-5.6 All versions
Ubuntu:20.04:LTS canonical linux-oracle-5.11 All versions
Ubuntu:20.04:LTS canonical linux-oracle-5.13 All versions
Ubuntu:Pro:20.04:LTS canonical linux-oracle-5.15 All versions
Showing 50 of 217. Show the rest
Ecosystem VendorProductAffected versions
Ubuntu:20.04:LTS canonical linux-oracle-5.8 All versions
Ubuntu:20.04:LTS canonical linux-raspi2 All versions
Ubuntu:20.04:LTS canonical linux-riscv All versions
Ubuntu:20.04:LTS canonical linux-riscv-5.11 All versions
Ubuntu:Pro:20.04:LTS canonical linux-riscv-5.15 All versions
Ubuntu:20.04:LTS canonical linux-riscv-5.8 All versions
Ubuntu:22.04:LTS canonical linux All versions
Ubuntu:22.04:LTS canonical linux-allwinner-5.19 All versions
Ubuntu:22.04:LTS canonical linux-aws All versions
Ubuntu:22.04:LTS canonical linux-aws-5.19 All versions
Ubuntu:22.04:LTS canonical linux-aws-6.2 All versions
Ubuntu:22.04:LTS canonical linux-aws-6.5 All versions
Ubuntu:22.04:LTS canonical linux-aws-6.8 All versions
Ubuntu:22.04:LTS canonical linux-azure All versions
Ubuntu:22.04:LTS canonical linux-azure-5.19 All versions
Ubuntu:22.04:LTS canonical linux-azure-6.2 All versions
Ubuntu:22.04:LTS canonical linux-azure-6.5 All versions
Ubuntu:22.04:LTS canonical linux-azure-6.8 All versions
Ubuntu:22.04:LTS canonical linux-azure-fde All versions
Ubuntu:22.04:LTS canonical linux-azure-fde-5.19 All versions
Ubuntu:22.04:LTS canonical linux-azure-fde-6.2 All versions
Ubuntu:22.04:LTS canonical linux-azure-fde-6.8 All versions
Ubuntu:22.04:LTS canonical linux-gcp All versions
Ubuntu:22.04:LTS canonical linux-gcp-5.19 All versions
Ubuntu:22.04:LTS canonical linux-gcp-6.2 All versions
Ubuntu:22.04:LTS canonical linux-gcp-6.5 All versions
Ubuntu:22.04:LTS canonical linux-gcp-6.8 All versions
Ubuntu:22.04:LTS canonical linux-gke All versions
Ubuntu:22.04:LTS canonical linux-gkeop All versions
Ubuntu:22.04:LTS canonical linux-hwe-5.19 All versions
Ubuntu:22.04:LTS canonical linux-hwe-6.2 All versions
Ubuntu:22.04:LTS canonical linux-hwe-6.5 All versions
Ubuntu:22.04:LTS canonical linux-hwe-6.8 All versions
Ubuntu:22.04:LTS canonical linux-ibm All versions
Ubuntu:22.04:LTS canonical linux-ibm-6.8 All versions
Ubuntu:22.04:LTS canonical linux-intel-iot-realtime All versions
Ubuntu:22.04:LTS canonical linux-intel-iotg All versions
Ubuntu:22.04:LTS canonical linux-kvm All versions
Ubuntu:22.04:LTS canonical linux-lowlatency All versions
Ubuntu:22.04:LTS canonical linux-lowlatency-hwe-5.19 All versions
Ubuntu:22.04:LTS canonical linux-lowlatency-hwe-6.2 All versions
Ubuntu:22.04:LTS canonical linux-lowlatency-hwe-6.5 All versions
Ubuntu:22.04:LTS canonical linux-lowlatency-hwe-6.8 All versions
Ubuntu:22.04:LTS canonical linux-nvidia All versions
Ubuntu:22.04:LTS canonical linux-nvidia-6.2 All versions
Ubuntu:22.04:LTS canonical linux-nvidia-6.5 All versions
Ubuntu:22.04:LTS canonical linux-nvidia-6.8 All versions
Ubuntu:22.04:LTS canonical linux-nvidia-tegra All versions
Ubuntu:22.04:LTS canonical linux-nvidia-tegra-igx All versions
Ubuntu:22.04:LTS canonical linux-oem-5.17 All versions
Ubuntu:22.04:LTS canonical linux-oem-6.0 All versions
Ubuntu:22.04:LTS canonical linux-oem-6.1 All versions
Ubuntu:22.04:LTS canonical linux-oem-6.5 All versions
Ubuntu:22.04:LTS canonical linux-oracle All versions
Ubuntu:22.04:LTS canonical linux-oracle-6.5 All versions
Ubuntu:22.04:LTS canonical linux-oracle-6.8 All versions
Ubuntu:22.04:LTS canonical linux-raspi All versions
Ubuntu:22.04:LTS canonical linux-realtime All versions
Ubuntu:22.04:LTS canonical linux-riscv All versions
Ubuntu:22.04:LTS canonical linux-riscv-5.19 All versions
Ubuntu:22.04:LTS canonical linux-riscv-6.5 All versions
Ubuntu:22.04:LTS canonical linux-riscv-6.8 All versions
Ubuntu:22.04:LTS canonical linux-starfive-5.19 All versions
Ubuntu:22.04:LTS canonical linux-starfive-6.2 All versions
Ubuntu:22.04:LTS canonical linux-starfive-6.5 All versions
Ubuntu:22.04:LTS canonical linux-xilinx-zynqmp All versions
Ubuntu:Nvidia-BlueField:22.04:LTS canonical linux-bluefield All versions
Ubuntu:Pro:FIPS-preview:22.04:LTS canonical linux-aws-fips All versions
Ubuntu:Pro:FIPS-preview:22.04:LTS canonical linux-azure-fips All versions
Ubuntu:Pro:FIPS-preview:22.04:LTS canonical linux-fips All versions
Ubuntu:Pro:FIPS-preview:22.04:LTS canonical linux-gcp-fips All versions
Ubuntu:Pro:FIPS-updates:22.04:LTS canonical linux-aws-fips All versions
Ubuntu:Pro:FIPS-updates:22.04:LTS canonical linux-azure-fips All versions
Ubuntu:Pro:FIPS-updates:22.04:LTS canonical linux-fips All versions
Ubuntu:Pro:FIPS-updates:22.04:LTS canonical linux-gcp-fips All versions
Ubuntu:Pro:Realtime:22.04:LTS canonical linux-intel-iot-realtime All versions
Ubuntu:Pro:Realtime:22.04:LTS canonical linux-realtime All versions
Ubuntu:Pro:Realtime:22.04:LTS canonical linux-realtime-6.8 All versions
Ubuntu:24.04:LTS canonical linux < 6.8.0-147.147
Fix: upgrade to 6.8.0-147.147
Ubuntu:24.04:LTS canonical linux-aws < 6.8.0-1067.70
Fix: upgrade to 6.8.0-1067.70
Ubuntu:24.04:LTS canonical linux-aws-6.14 All versions
Ubuntu:24.04:LTS canonical linux-aws-6.17 All versions
Ubuntu:24.04:LTS canonical linux-azure < 6.8.0-1071.79
Fix: upgrade to 6.8.0-1071.79
Ubuntu:24.04:LTS canonical linux-azure-6.11 All versions
Ubuntu:24.04:LTS canonical linux-azure-6.14 All versions
Ubuntu:24.04:LTS canonical linux-azure-6.17 All versions
Ubuntu:24.04:LTS canonical linux-azure-fde < 6.8.0-1069.76
Fix: upgrade to 6.8.0-1069.76
Ubuntu:24.04:LTS canonical linux-azure-fde-6.14 All versions
Ubuntu:24.04:LTS canonical linux-azure-fde-6.17 All versions
Ubuntu:24.04:LTS canonical linux-azure-nvidia All versions
Ubuntu:24.04:LTS canonical linux-azure-nvidia-6.14 All versions
Ubuntu:24.04:LTS canonical linux-gcp < 6.8.0-1071.79
Fix: upgrade to 6.8.0-1071.79
Ubuntu:24.04:LTS canonical linux-gcp-6.11 All versions
Ubuntu:24.04:LTS canonical linux-gcp-6.14 All versions
Ubuntu:24.04:LTS canonical linux-gcp-6.17 All versions
Ubuntu:24.04:LTS canonical linux-gke < 6.8.0-1066.74
Fix: upgrade to 6.8.0-1066.74
Ubuntu:24.04:LTS canonical linux-gkeop < 6.8.0-1052.56
Fix: upgrade to 6.8.0-1052.56
Ubuntu:24.04:LTS canonical linux-hwe-6.11 All versions
Ubuntu:24.04:LTS canonical linux-hwe-6.14 All versions
Ubuntu:24.04:LTS canonical linux-hwe-6.17 All versions
Ubuntu:24.04:LTS canonical linux-hwe-7.0 < 7.0.0-28.28~24.04.1
Fix: upgrade to 7.0.0-28.28~24.04.1
Ubuntu:24.04:LTS canonical linux-ibm < 6.8.0-1067.68
Fix: upgrade to 6.8.0-1067.68
Ubuntu:24.04:LTS canonical linux-lowlatency < 6.8.0-147.147.1
Fix: upgrade to 6.8.0-147.147.1
Ubuntu:24.04:LTS canonical linux-lowlatency-hwe-6.11 All versions
Ubuntu:24.04:LTS canonical linux-nvidia All versions
Ubuntu:24.04:LTS canonical linux-nvidia-6.11 All versions
Ubuntu:24.04:LTS canonical linux-nvidia-6.17 All versions
Ubuntu:24.04:LTS canonical linux-nvidia-7.0 < 7.0.0-1016.16~24.04.1
Fix: upgrade to 7.0.0-1016.16~24.04.1
Ubuntu:24.04:LTS canonical linux-nvidia-lowlatency All versions
Ubuntu:24.04:LTS canonical linux-nvidia-tegra < 6.8.0-1035.38
Fix: upgrade to 6.8.0-1035.38
Ubuntu:24.04:LTS canonical linux-oem-6.11 All versions
Ubuntu:24.04:LTS canonical linux-oem-6.14 All versions
Ubuntu:24.04:LTS canonical linux-oem-6.17 All versions
Ubuntu:24.04:LTS canonical linux-oem-6.8 All versions
Ubuntu:24.04:LTS canonical linux-oracle < 6.8.0-1064.67
Fix: upgrade to 6.8.0-1064.67
Ubuntu:24.04:LTS canonical linux-oracle-6.14 All versions
Ubuntu:24.04:LTS canonical linux-oracle-6.17 All versions
Ubuntu:24.04:LTS canonical linux-raspi All versions
Ubuntu:24.04:LTS canonical linux-raspi-realtime All versions
Ubuntu:24.04:LTS canonical linux-realtime All versions
Ubuntu:24.04:LTS canonical linux-riscv All versions
Ubuntu:24.04:LTS canonical linux-riscv-6.14 All versions
Ubuntu:24.04:LTS canonical linux-riscv-6.17 All versions
Ubuntu:24.04:LTS canonical linux-riscv-7.0 < 7.0.0-28.28.1~24.04.3
Fix: upgrade to 7.0.0-28.28.1~24.04.3
Ubuntu:24.04:LTS canonical linux-xilinx All versions
Ubuntu:Nvidia-BlueField:24.04:LTS canonical linux-bluefield < 6.8.0-1033.38
Fix: upgrade to 6.8.0-1033.38
Ubuntu:Pro:FIPS-updates:24.04:LTS canonical linux-aws-fips < 6.8.0-1067.70+fips1
Fix: upgrade to 6.8.0-1067.70+fips1
Ubuntu:Pro:FIPS-updates:24.04:LTS canonical linux-azure-fips < 6.8.0-1071.79+fips1
Fix: upgrade to 6.8.0-1071.79+fips1
Ubuntu:Pro:FIPS-updates:24.04:LTS canonical linux-fips < 6.8.0-147.147+fips1
Fix: upgrade to 6.8.0-147.147+fips1
Ubuntu:Pro:FIPS-updates:24.04:LTS canonical linux-gcp-fips < 6.8.0-1071.79+fips1
Fix: upgrade to 6.8.0-1071.79+fips1
Ubuntu:Pro:Realtime:24.04:LTS canonical linux-raspi-realtime All versions
Ubuntu:Pro:Realtime:24.04:LTS canonical linux-realtime < 6.8.1-1062.63
Fix: upgrade to 6.8.1-1062.63
Ubuntu:Pro:Realtime:24.04:LTS canonical linux-realtime-6.14 All versions
Ubuntu:Pro:Realtime:24.04:LTS canonical linux-realtime-6.17 All versions
Ubuntu:26.04:LTS canonical linux < 7.0.0-28.28
Fix: upgrade to 7.0.0-28.28
Ubuntu:26.04:LTS canonical linux-aws < 7.0.0-1009.9
Fix: upgrade to 7.0.0-1009.9
Ubuntu:26.04:LTS canonical linux-azure < 7.0.0-1010.10
Fix: upgrade to 7.0.0-1010.10
Ubuntu:26.04:LTS canonical linux-azure-fde < 7.0.0-1009.9
Fix: upgrade to 7.0.0-1009.9
Ubuntu:26.04:LTS canonical linux-gcp < 7.0.0-1008.8
Fix: upgrade to 7.0.0-1008.8
Ubuntu:26.04:LTS canonical linux-gke < 7.0.0-1003.4
Fix: upgrade to 7.0.0-1003.4
Ubuntu:26.04:LTS canonical linux-ibm < 7.0.0-1010.10
Fix: upgrade to 7.0.0-1010.10
Ubuntu:26.04:LTS canonical linux-nvidia < 7.0.0-1016.16
Fix: upgrade to 7.0.0-1016.16
Ubuntu:26.04:LTS canonical linux-nvidia-bos < 7.0.0-2016.16
Fix: upgrade to 7.0.0-2016.16
Ubuntu:26.04:LTS canonical linux-oem-7.0 < 7.0.0-1009.9
Fix: upgrade to 7.0.0-1009.9
Ubuntu:26.04:LTS canonical linux-oracle < 7.0.0-1008.8
Fix: upgrade to 7.0.0-1008.8
Ubuntu:26.04:LTS canonical linux-raspi < 7.0.0-1015.15
Fix: upgrade to 7.0.0-1015.15
Ubuntu:26.04:LTS canonical linux-realtime < 7.0.0-28.28.1
Fix: upgrade to 7.0.0-28.28.1
Ubuntu:26.04:LTS canonical linux-riscv < 7.0.0-28.28.1
Fix: upgrade to 7.0.0-28.28.1
Ubuntu:24.04:LTS canonical linux-azure-7.0 < 7.0.0-1014.14~24.04.1
Fix: upgrade to 7.0.0-1014.14~24.04.1
Ubuntu:24.04:LTS canonical linux-gcp-7.0 < 7.0.0-1011.11~24.04.1
Fix: upgrade to 7.0.0-1011.11~24.04.1
Ubuntu:24.04:LTS canonical linux-oracle-7.0 < 7.0.0-1011.11~24.04.1
Fix: upgrade to 7.0.0-1011.11~24.04.1
Root:Debian:12 debian rootio-linux < 6.1.177-1.root.io.161
Fix: upgrade to 6.1.177-1.root.io.161
– linux linux < 3b6035bc6bff20e89752ce4358bc4c9a9d5883f2
5.11
Debian:12 debian linux All versions
Debian:13 debian linux < 6.12.95-1
Fix: upgrade to 6.12.95-1
Debian:14 debian linux < 7.0.12-1
Fix: upgrade to 7.0.12-1
Ubuntu:24.04:LTS canonical linux-azure-fde-7.0 < 7.0.0-1013.13~24.04.1
Fix: upgrade to 7.0.0-1013.13~24.04.1
Root:Ubuntu:22.04 – linux < 5.15.0-198.208.aikido.116
< 5.15.0-202.212.aikido.118
Fix: upgrade to 5.15.0-198.208.aikido.116
Root:Ubuntu:22.04 – rootio-linux < 5.15.0-198.208.aikido.116
< 5.15.0-202.212.aikido.118
Fix: upgrade to 5.15.0-198.208.aikido.116
Ubuntu:24.04:LTS canonical linux-vmware All versions
Linux linux kernel >= 6.19.0, < 7.0.12
Fix: upgrade to 7.0.12
Root:Debian:12 – linux < 6.1.190-1.aikido.167
Fix: upgrade to 6.1.190-1.aikido.167
Root:Debian:12 – rootio-linux < 6.1.190-1.aikido.167
Fix: upgrade to 6.1.190-1.aikido.167
– linux linux_kernel >= 5.11, < 6.6.160
>= 6.7, < 6.12.95
>= 6.13, < 6.18.35
>= 6.19, < 7.0.12
7.1
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Alpaquita:23 bellsoft linux-lts >= 6.1.189-r0, < 6.1.191-r0
Fix: upgrade to 6.1.191-r0
Alpaquita:25 bellsoft linux-lts >= 6.12.92-r0, < 6.12.95-r0
Fix: upgrade to 6.12.95-r0
Alpaquita:stream bellsoft linux-lts >= 6.12.92-r1, < 6.18.35-r1
Fix: upgrade to 6.18.35-r1
Original advisory text
BELL-CVE-2026-63940
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.
References
Fix within
Internet-facing 14 days
Internal At next upgrade
  • Not known to be exploited
  • Needs hands-on effort to exploit
  • Gives an attacker full control
Severity
8.9 High
Exploitation
<1% chance of attack within 30 days
Type
CWE-190Integer Overflow
CWE-191Integer Underflow (Wrap or Wraparound)
Timeline
Published22 Jul 2026
Updated4 Nov 2026
First seen19 Jul 2026
Track software like this
Free during beta