CVE intelligence and bounded remediation

CVE-2026-43363 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: x86/apic: Disable x2apic on resume if the kernel expects so When resuming from s2ram, firmware may re-enable x2apic mode, which may have been disabled by the kernel during boot either because it doesn't support IRQ remapping or for other reasons. This causes the kernel to continue using the xapic interface, while the hardware is in x2apic mode, which causes hangs. This happens on defconfig + bare metal + s2ram. Fix this in lapic_resume() by disabling x2apic if the kernel expects it to be disabled, i.e. when x2apic_mode = 0. The ACPI v6.6 spec, Section 16.3 [1] says firmware restores either the pre-sleep configuration or initial boot configuration for each CPU, including MSR state: When executing from the power-on reset vector as a result of waking from an S2 or S3 sleep state, the platform firmware performs only the hardware initialization required to restore the system to either the state the platform was in prior to the initial operating system boot, or to the pre-sleep configuration state. In multiprocessor systems, non-boot processors should be placed in the same state as prior to the initial operating system…

Severity
Medium
CVSS
5.5 (3.1)
Published
2026-05-08
CISA KEV
Not currently listed
Ecosystem
linux/kernel

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 7.0

Showing 2 representative product identities from 10 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

General vulnerability remediation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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