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CVE-2026-109836NVD status: Deferred

Core Temp: Exposed IOCTL with Insufficient Access Control

CVE-2026-109836 is a high-severity exposed IOCTL with insufficient access control vulnerability in Core Temp from ALCPU, with a CVSS 4.0 base score of 8.4 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. The record lists version 1.21 as the first without the flaw, so updating Core Temp to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.12% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Core Temp to 1.21 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
ALCPUCore Tempbefore 1.211.21

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (jpcert.or.jp).

Scoring systemScoreSeverityScored by
CVSS 4.08.4HighCNA (jpcert.or.jp)
CVSS 3.06.7MediumCNA (jpcert.or.jp)

Official description

The Core Temp kernel driver provided by ALCPU is vulnerable to insufficient access control in an exposed IOCTL, which may allow physical memory to be read or written.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Exposed IOCTL with Insufficient Access Control

The product implements an IOCTL with functionality that should be restricted, but it does not properly enforce access control for the IOCTL.

How developers prevent this class of flaw

  • In Windows environments, use proper access control for the associated device or device namespace. See References.

More Exposed IOCTL with Insufficient Access Control vulnerabilities (CWE-782)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Exposed IOCTL with Insufficient Access Control vulnerabilities

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