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Vulnerability · Published Sep 17, 2026 · Assigned by Linux

CVE-2026-93186cxl/mbox: Clamp mailbox output allocation to the payload size

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 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 90.2% 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: cxl/mbox: Clamp mailbox output allocation to the payload size CXL_MEM_SEND_COMMAND bounds the user's in.size to the mailbox payload size but leaves out.size unbounded, then cxl_mbox_cmd_ctor() calls kvzalloc(out.size). A large out.size drives a huge allocation, above INT_MAX it WARNs and taints, and with panic_on_warn=1 it panics. The transport __cxl_pci_mbox_send_cmd() already clamps the response copy to min(out.size, payload_size, device len), so the output buffer is never written beyond payload_size. Clamp the allocation to payload_size too, matching the RAW path.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linuxno fix listedDEBIAN-CVE-2026-93186
Debian:13linux6.12.111-1DEBIAN-CVE-2026-93186
Debian:14linux7.2.6-1DEBIAN-CVE-2026-93186
Debian:12linux-6.126.12.111-1~deb12u1DEBIAN-CVE-2026-93186
Ubuntu:22.04:LTSlinuxno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinuxno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux7.0.0-42.42UBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-aws7.0.0-1016.17UBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-aws-7.0no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-7.0no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-fde-7.0no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-gcp7.0.0-1016.18UBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-gcp-7.0no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-42.42~24.04.1UBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-ibm7.0.0-1017.17UBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-intel-iotgno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-kvmno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-nvidia-7.0no fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-nvidia-bosno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-nvidia-tegra-igxno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1017.17UBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-oracle7.0.0-1015.16UBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-oracle-7.0no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-93186
Ubuntu:26.04:LTSlinux-riscv7.0.0-42.42.1UBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-42.42.1~24.04.1UBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-vmwareno fix listedUBUNTU-CVE-2026-93186
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-93186
Ubuntu:22.04:LTSlinux-xilinx-zynqmpno fix listedUBUNTU-CVE-2026-93186

Affected products (as reported)

VendorProductVersions
Linux Linux 583fa5e71caeb79e04e477e9837e2f7fa53b71e4 – before 123f6d154253939ce38f0ec0b6d1ba67f870e01f583fa5e71caeb79e04e477e9837e2f7fa53b71e4 – before d2d40574b9b272ade32d0d77b140d990e7547f5f583fa5e71caeb79e04e477e9837e2f7fa53b71e4 – before f5d2bbf0300f46307948864fbb97bce5097f4fe2583fa5e71caeb79e04e477e9837e2f7fa53b71e4 – before 31d4841eca7c4b75751ca96d24339e19303337f2583fa5e71caeb79e04e477e9837e2f7fa53b71e4 – before b4e11c731d6bee3b87315e055a1ca417c92dc1fc583fa5e71caeb79e04e477e9837e2f7fa53b71e4 – before 8a13db9f899d149c3aab24abcb668121cfda5a4f
Linux Linux 5.12

References