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VulnerabilityPublished Updated

CVE-2026-74549: Linux kernel · hwmon: (nct6775-core) Prevent access to unsupported weight registers

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +28
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-5.5 – 7.0.0-38.38
23 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1014.14
15 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1003.3 – 7.0.0-1017.17
15 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1016.16
9 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1014.14
13 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1002.3 – 7.0.0-1008.9
6 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (nct6775-core) Prevent access to unsupported weight registers Sashiko reports: During initialization of the nct6116 chip, the driver sets data->pwm_num to 5. However, it assigns several NCT6106 register arrays (such as NCT6106_REG_WEIGHT_DUTY_STEP, NCT6106_REG_WEIGHT_TEMP_SEL, and NCT6106_REG_WEIGHT_TEMP_*) to data->REG_PWM and data->REG_WEIGHT_TEMP. These arrays only contain 3 elements. In nct6775_update_pwm(), the driver iterates up to data->pwm_num. If data->has_pwm has bits 3 or 4 set (which is structurally possible for nct6116), the loop attempts to read elements at index 3 and 4 from these 3-element arrays. This results in a global out-of-bounds read, which can be caught by KASAN. Furthermore, the driver uses these garbage out-of-bounds values as hardware register addresses for subsequent read and write operations. This leads to invalid hardware register access, potentially causing hardware misconfiguration or system crashes. The underlying problem is that the chip does support up to five fan control channels, but only the first three support weight control. Fix the problem by extending the affected weight register arrays with zeroed fields. The driver uses zeroed register addresses to determine if a register is supported or not, and skips accesses for unsupported registers.

References

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