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Vulnerability · Published Jun 24, 2026 · Assigned by Linux

CVE-2026-53042fwctl: Fix class init ordering to avoid NULL pointer dereference on device removal

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 94.8% 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: fwctl: Fix class init ordering to avoid NULL pointer dereference on device removal CXL is linked before fwctl in drivers/Makefile. Both use `module_init, so `cxl_pci_driver_init()` runs first. When `cxl_pci_probe()` calls `fwctl_register()` and then `device_add()`, fwctl_class is not yet registered because fwctl_init() hasn't run, causing `class_to_subsys()` to return NULL and skip knode_class initialization. On device removal, `class_to_subsys()` returns non-NULL, and `device_del()` calls `klist_del()` on the uninitialized knode, triggering a NULL pointer dereference.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:14linux7.0.10-1DEBIAN-CVE-2026-53042
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux7.0.0-28.28UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-aws7.0.0-1009.9UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-azure7.0.0-1010.10UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-53042
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1009.9UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-gcp7.0.0-1008.8UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-gke7.0.0-1003.4UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-28.28~24.04.1UBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-ibm7.0.0-1010.10UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1016.16UBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-nvidia-6.176.17.0-1018.18UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1016.16~24.04.1UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1009.9UBUNTU-CVE-2026-53042
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-oracle7.0.0-1008.8UBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-53042
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-raspi7.0.0-1015.15UBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-53042
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-realtime7.0.0-28.28.1UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-53042
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-53042
Ubuntu:26.04:LTSlinux-riscv7.0.0-28.28.1UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-53042
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-28.28.1~24.04.3UBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-53042
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-53042

Affected products (as reported)

VendorProductVersions
Linux Linux 858ce2f56b5253063f61f6b1c58a6dbf5d71da0b – before a28f56988c8e5bb9375806a5cfb0bf54d662ae3f858ce2f56b5253063f61f6b1c58a6dbf5d71da0b – before 1075f2f590fdac147f8b8010c35b606564b5c7d7858ce2f56b5253063f61f6b1c58a6dbf5d71da0b – before a55f80233f384dc89ef3425b2e1dd0e6d44bcf29
Linux Linux 6.15

References