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CVE Record

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

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue affects a specialized performance-monitoring path for Intel uncore hardware. Under certain boot and CPU topology conditions, the kernel can write past an array boundary. The public record describes warnings and possible other issues, but does not provide CVSS, exploit evidence, or a clear impact category.

Executive priority

Treat this as a targeted kernel stability and integrity issue, not an emergency internet-facing incident based on current sources. Patch through normal kernel maintenance, with higher priority for affected production hosts using Intel hardware and custom CPU topology settings.

Technical view

The flaw is in perf/x86/intel/uncore discovery handling. When NUMA is disabled and all CPUs in an associated die are offline, discovery parsing can continue and overflow pmu->boxes[die] during uncore_pci_pmu_register(). Stable commits resolve this by skipping discovery tables for offline dies.

Likely exposure

Likely exposure is limited to Linux systems using affected kernel versions on Intel x86 platforms where the intel_uncore path is present and CPU topology can include offline dies, especially NUMA-disabled configurations.

Exploitation context

The source bundle marks KEV as false and provides no evidence of active exploitation, public exploit code, or remote attackability. The described trigger is configuration and topology dependent.

Researcher notes

Evidence is limited to the CVE record and Linux stable references. No CVSS, CWE, exploitability analysis, or concrete security impact beyond array overflow, warning, and possible other issues is provided. Validate against vendor backports rather than raw upstream version strings alone.

Mitigation direction

  • Update to a Linux kernel containing the referenced stable fixes.
  • Check distribution advisories for backported fixes matching your deployed kernel branch.
  • Prioritize affected Intel x86 systems with NUMA disabled or unusual CPU boot limits.
  • Avoid assuming a fix version unless your vendor maps it to this CVE.

Validation and detection

  • Inventory Linux kernel versions across Intel x86 systems.
  • Check whether NUMA is disabled or CPUs are intentionally offline at boot.
  • Review boot logs for intel_uncore warnings matching the CVE description.
  • Confirm installed kernel includes the applicable stable commit or vendor backport.
Prepared
Confidence
medium
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2026-43079 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
8Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxedae1f06c2cda41edffc93de6aedc8ba8dc883c3, edae1f06c2cda41edffc93de6aedc8ba8dc883c3, edae1f06c2cda41edffc93de6aedc8ba8dc883c3, edae1f06c2cda41edffc93de6aedc8ba8dc883c3, edae1f06c2cda41edffc93de6aedc8ba8dc883c3, edae1f06c2cda41edffc93de6aedc8ba8dc883c3, edae1f06c2cda41edffc93de6aedc8ba8dc883c3unaffected
LinuxLinux5.13, 0, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.