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Vulnerability · Published Sep 11, 2026 · Assigned by Linux

CVE-2026-89751x86/tdx: Fix off-by-one in port I/O handling

Unrated

In plain English

A security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 93.3% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix off-by-one in port I/O handling handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use: u64 mask = GENMASK(BITS_PER_BYTE * size, 0); GENMASK(h, l) includes bit h. For size=1 (INB), this produces GENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8 bits). The mask is one bit too wide for all I/O sizes. Fix the mask calculation.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.190-1DEBIAN-CVE-2026-89751
Debian:13linux6.12.111-1DEBIAN-CVE-2026-89751
Debian:14linux7.2.6-1DEBIAN-CVE-2026-89751
Debian:12linux-6.126.12.111-1~deb12u1DEBIAN-CVE-2026-89751
Ubuntu:24.04:LTSlinuxno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux7.0.0-42.42UBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-aws7.0.0-1016.17UBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-aws-7.0no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-7.0no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-fde-7.0no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-gcp7.0.0-1016.18UBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-gcp-7.0no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-42.42~24.04.1UBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-ibm7.0.0-1017.17UBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-nvidia-7.0no fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-nvidia-bosno fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1017.17UBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-oracle7.0.0-1015.16UBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-oracle-7.0no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-89751
Ubuntu:26.04:LTSlinux-riscv7.0.0-42.42.1UBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-42.42.1~24.04.1UBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-89751
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-vmwareno fix listedUBUNTU-CVE-2026-89751
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-89751

Affected products (as reported)

VendorProductVersions
Linux Linux 03149948832a078f759022ed5b92e722d8d23c26 – before c6875423ad849ac234ab9812eb72f37ff8a490b403149948832a078f759022ed5b92e722d8d23c26 – before 220011fe95fc78b2bc2d7d43893bc73957a5c81103149948832a078f759022ed5b92e722d8d23c26 – before 222b7005e4519f633b4cd666226256abbab46a1a03149948832a078f759022ed5b92e722d8d23c26 – before c4a22154870813d10aa0b4c734a574c726f9d4b003149948832a078f759022ed5b92e722d8d23c26 – before bb45f705c4440dd3c689328319b88dd28770bbb803149948832a078f759022ed5b92e722d8d23c26 – before 0f63e656b1c679d32ac595de29d10c03efca6a25
Linux Linux 5.19

References