Log in Start free

Vulnerability · Published May 27, 2026 · Assigned by Linux

CVE-2026-45865mctp i2c: initialise event handler read bytes

Medium 5.5

In plain English

A medium-severity 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 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 94.7% 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: mctp i2c: initialise event handler read bytes Set a 0xff value for i2c reads of an mctp-i2c device. Otherwise reads will return "val" from the i2c bus driver. For i2c-aspeed and i2c-npcm7xx that is a stack uninitialised u8. Tested with "i2ctransfer -y 1 r10@0x34" where 0x34 is a mctp-i2c instance, now it returns all 0xff.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.170-1DEBIAN-CVE-2026-45865
Debian:13linux6.12.85-1DEBIAN-CVE-2026-45865
Debian:14linux6.18.14-1DEBIAN-CVE-2026-45865
Ubuntu:24.04:LTSlinux6.8.0-134.134UBUNTU-CVE-2026-45865
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-aws6.8.0-1060.63UBUNTU-CVE-2026-45865
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1060.63~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71UBUNTU-CVE-2026-45865
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69UBUNTU-CVE-2026-45865
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-gcp6.8.0-1063.69UBUNTU-CVE-2026-45865
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1063.69~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-gke6.8.0-1058.64UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1045.48UBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-ibm6.8.0-1060.61UBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1060.61~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-134.134.1UBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-134.134.1~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1058.61UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1058.61~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1058.61.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1029.30UBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-oracle6.8.0-1057.58UBUNTU-CVE-2026-45865
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1057.58~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-raspi6.8.0-1060.64UBUNTU-CVE-2026-45865
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-45865
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-45865
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-134.134~22.04.1UBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-45865
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-45865
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1032.33UBUNTU-CVE-2026-45865

Affected products (as reported)

VendorProductVersions
Linux Linux f5b8abf9fc3dacd7529d363e26fe8230935d65f8 – before 93e01e837e105299f1c259ef71f6e1ec4fe806e3f5b8abf9fc3dacd7529d363e26fe8230935d65f8 – before 11f83253244060b5de5eac787f61ae3f3e559d01f5b8abf9fc3dacd7529d363e26fe8230935d65f8 – before fa9861e5c8af7651dddfa8d490aaada17ae33b6cf5b8abf9fc3dacd7529d363e26fe8230935d65f8 – before 6ff2ebfef75fbc57d937d8fbe738b967edf2d331f5b8abf9fc3dacd7529d363e26fe8230935d65f8 – before 1eeedb310229bfee9dd4d992e5bba33fe1378a8ff5b8abf9fc3dacd7529d363e26fe8230935d65f8 – before 2a14e91b6d76639dac70ea170f4384c1ee3cb48d
Linux Linux 5.18

References