LiveActive security incident?Get immediate response
CVE Record

CVE-2026-23323: hwmon: (macsmc) Fix regressions in Apple Silicon SMC hwmon driver

In the Linux kernel, the following vulnerability has been resolved: hwmon: (macsmc) Fix regressions in Apple Silicon SMC hwmon driver The recently added macsmc-hwmon driver contained several critical bugs in its sensor population logic and float conversion routines. Specifically: - The voltage sensor population loop used the wrong prefix ("volt-" instead of "voltage-") and incorrectly assigned sensors to the temperature sensor array (hwmon->temp.sensors) instead of the voltage sensor array (hwmon->volt.sensors). This would lead to out-of-bounds memory access or data corruption when both temperature and voltage sensors were present. - The float conversion in macsmc_hwmon_write_f32() had flawed exponent logic for values >= 2^24 and lacked masking for the mantissa, which could lead to incorrect values being written to the SMC. Fix these issues to ensure correct sensor registration and reliable manual fan control. Confirm that the reported overflow in FIELD_PREP is fixed by declaring macsmc_hwmon_write_f32() as __always_inline for a compile test.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue affects the Apple Silicon SMC hardware monitoring driver. The bug can mis-handle temperature and voltage sensors, causing out-of-bounds memory access or data corruption, and can write incorrect values to the SMC. The sources do not provide a CVSS score, attack path, or evidence of exploitation.

Executive priority

Handle as a targeted kernel maintenance item, not a broad internet emergency. Prioritize affected Apple Silicon Linux assets, especially systems where hardware monitoring or fan control reliability matters. Broader urgency is limited by missing exploitation evidence and hardware-specific exposure.

Technical view

The macsmc-hwmon driver used the wrong voltage sensor prefix and stored voltage entries in the temperature sensor array. Its f32 conversion also had flawed exponent handling and missing mantissa masking. The upstream fix corrects sensor registration and manual fan control behavior, with an inline change for compile-time FIELD_PREP overflow validation.

Likely exposure

Exposure appears limited to Linux systems on Apple Silicon using the macsmc-hwmon driver in source-marked affected kernel ranges. The bundle lists Linux 6.19 through 6.19.7 and 7.0 as affected, but distribution backports and package status must be checked with vendors.

Exploitation context

No active exploitation is supported by the supplied sources, and the CVE is not marked KEV. The source bundle does not describe remote exploitation, required privileges, or a public exploit. Treat this as a kernel reliability and memory-safety issue requiring targeted validation.

Researcher notes

Key impact evidence is out-of-bounds access or data corruption during sensor population, plus incorrect SMC writes from f32 conversion. The supplied record does not identify a privilege boundary, trigger path, CVSS vector, CWE, or exploitability details, so further triage should focus on driver reachability and vendor-fixed kernel lineage.

Mitigation direction

  • Check Linux vendor guidance for kernels containing the referenced stable fixes.
  • Prioritize updates for Apple Silicon Linux hosts using macsmc-hwmon.
  • Confirm distribution kernels include the upstream stable commits or equivalent backports.
  • Do not rely on manual fan control behavior until a fixed kernel is installed.

Validation and detection

  • Inventory Apple Silicon Linux systems and their running kernel versions.
  • Determine whether macsmc-hwmon is present or enabled on those systems.
  • Compare installed kernel source or changelog against the referenced stable commits.
  • Review vendor advisories for backported fixes and affected package versions.
Prepared
Confidence
medium
Sources
4

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2026-23323 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
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
3Source 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
LinuxLinux785205fd81399bd8e49065aee3362a99d5702321, 785205fd81399bd8e49065aee3362a99d5702321unaffected
LinuxLinux6.19, 0, 6.19.7, 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.