Vulnerability · Published Sep 15, 2025 · Assigned by Linux

CVE-2023-53205KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler

High 7.3

In plain English

A high-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 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.3High
Exploit odds (30 days)0.2%top 93.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler We do check for target CPU == -1, but this might change at the time we are going to use it. Hold the physical target CPU in a local variable to avoid out-of-bound accesses to the cpu arrays.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.52-1DEBIAN-CVE-2023-53205
Debian:13linux6.4.4-1DEBIAN-CVE-2023-53205
Debian:14linux6.4.4-1DEBIAN-CVE-2023-53205
Ubuntu:22.04:LTSlinux5.15.0-86.96UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-aws5.15.0-1047.52UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-azure5.15.0-1049.56UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1049.56.1UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-gcp5.15.0-1044.52UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-gke5.15.0-1044.49UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1030.35UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-ibm5.15.0-1040.43UBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1043.49UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-kvm5.15.0-1044.49UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-86.95UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1037.37UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1018.18UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1005.5UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-oracle5.15.0-1045.51UBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-raspi5.15.0-1040.43UBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53205
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2023-53205
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1025.29UBUNTU-CVE-2023-53205

Affected products (as reported)

VendorProductVersions
Linux Linux 87e28a15c42cc592009c32a8c20e5789059027c2 – before a9ccf140a2a03a0ae82be4bdfbdd17bdaea72ff587e28a15c42cc592009c32a8c20e5789059027c2 – before 86bfb18bad60fc468e5f112cbbd918462a8dd43587e28a15c42cc592009c32a8c20e5789059027c2 – before dc7e0192c470a53d847c79a2796f9ac429477a2687e28a15c42cc592009c32a8c20e5789059027c2 – before 0bc380beb78aa352eadbc21d934dd9606fcee808
Linux Linux 5.13

References