VULNpocalypse
HighVulnerabilityPatch available

Core Temp kernel driver IOCTL flaw disclosed by JVN, CVE-2026-109836

JVN discloses an exposed IOCTL flaw in the ALCPU Core Temp kernel driver before v1.21; update Core Temp to the latest version.

Published
Fixed in
Core Temp v1.21 or later, per JVN (affected versions are prior to v1.21)
Exploitation
No, exploitation is not confirmed and JVN does not report any

Live scores

CVE-2026-109836
EPSS
0.001
low predicted chance of attack
VEDAS
0.048
little exploit evidence
On CISA KEV
Not listed
Detection rule
No public rule yet

What happened

According to JVN, the Core Temp kernel driver from ALCPU exposes an IOCTL interface without enough access control (CWE-782). JVN is the vulnerability portal run by JPCERT/CC and IPA. The flaw is tracked as CVE-2026-109836. JVN published the advisory, JVN#23328936, on 2026-11-02, and the page shows the same date as its last update.

JVN says the impact is that “physical memory may be read or written.” It gives two scores:

  • CVSS 4.0: base score 8.4 (AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)
  • CVSS 3.0: base score 6.7 (AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H)

Both vectors say the attack is local and needs high privileges (JVN).

According to JVN, Tamaki Yanagawa reported the issue to IPA, and JPCERT/CC coordinated with the developer under the Information Security Early Warning Partnership.

Not confirmed from the sources:

  • whether the flaw has been exploited
  • whether a public proof of concept exists
  • which operating system versions are involved
  • any details from ALCPU itself beyond what JVN states

Am I affected?

JVN lists Core Temp prior to v1.21 as affected (JVN). If you have an older version installed, its kernel driver is in scope. JVN names no other ALCPU products.

What to do now

  1. Find every machine with Core Temp installed and check the version on each one.
  2. Update any copy older than v1.21 to the latest version, following the developer’s information, as JVN advises (JVN).
  3. Follow the NVD entry for CVE-2026-109836 and the JVN advisory for any changes to affected versions or exploitation status.

Sources