NULL pointer dereference in Linux

CVE-2026-43313

In the Linux kernel, the following vulnerability has been resolved: ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4() In acpi_processor_errata_piix4(), the pointer dev is first assigned an IDE device and then reassigned an ISA device: dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB, ...); dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB_0, ...); If the first lookup succeeds but the second fails, dev becomes NULL. This leads to a potential null-pointer dereference when dev_dbg() is called: if (errata.piix4.bmisx) dev_dbg(&dev->dev, ...); To prevent this, use two temporary pointers and retrieve each device independently, avoiding overwriting dev with a possible NULL value. [ rjw: Subject adjustment, added an empty code line ]

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (4.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 4.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-43313: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

  • Linux — versions 6.1.165, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 7.0
  • Linux Kernel — versions 2.6.12

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-43313?
CVE-2026-43313 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-05-08.
How severe is CVE-2026-43313?
Medium severity. CVSS v3 base score is 5.5 out of 10.