CVE-2026-43079: perf/x86/intel/uncore: Skip discovery table for offline dies

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-06 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel/uncore: Skip discovery table for offline dies This warning can be triggered if NUMA is disabled and the system boots with fewer CPUs than the number of CPUs in die 0. WARNING: CPU: 9 PID: 7257 at uncore.c:1157 uncore_pci_pmu_register+0x136/0x160 [intel_uncore] Currently, the discovery table continues to be parsed even if all CPUs in the associated die are offline. This can lead to an array overflow at "pmu->boxes[die] = box" in uncore_pci_pmu_register(), which may trigger the warning above or cause other issues.

Affected products

Linux kernel: from 5.13 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.136; from 6.7 before 6.12.83; from 6.13 before 6.18.24; from 6.19 before 6.19.14 — fixed in 5.15.209, 6.1.175, 6.12.83, 6.18.24, 6.19.14, 6.6.136

How to fix

Upgrade to a fixed version: Linux kernel 5.15.209, 6.1.175, 6.12.83, 6.18.24. Check the vendor advisory for mitigations.

References

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