Linux Kernel up to 7.2-rc5 nct6775-core nct6775_update_pwm pwm_num/has_pwm out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.00+

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel up to 6.6.150/6.12.102/6.18.43/7.1.7/7.2-rc5. Affected by this issue is the function nct6775_update_pwm of the component nct6775-core. The manipulation of the argument pwm_num/has_pwm results in out-of-bounds. This vulnerability is cataloged as CVE-2026-74549. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.6.150/6.12.102/6.18.43/7.1.7/7.2-rc5. Affected is the function nct6775_update_pwm of the component nct6775-core. The manipulation of the argument pwm_num/has_pwm with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-74549 since 08/15/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/15/2026).

Upgrading to version 6.6.151, 6.12.103, 6.18.44, 7.1.8 or 7.2-rc6 eliminates this vulnerability. Applying the patch 25b528816f5d83be5236dc182692369e8c9402b0/689082a4cb166a7ae9729f7b12339e69fdad6c52/1b722740ac5c2b2070f9ba922f4e0f227faf0246/4ad2972ef0e1bd1018ad7a72661a4636ed7daecc/d0b704e569ac3b8416d8e02270cdc9bf830ed395 is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-59742). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.151/6.12.103/6.18.44/7.1.8/7.2-rc6
Patch: 25b528816f5d83be5236dc182692369e8c9402b0/689082a4cb166a7ae9729f7b12339e69fdad6c52/1b722740ac5c2b2070f9ba922f4e0f227faf0246/4ad2972ef0e1bd1018ad7a72661a4636ed7daecc/d0b704e569ac3b8416d8e02270cdc9bf830ed395

Timelineinfo

08/15/2026 Advisory disclosed
08/15/2026 +0 days CVE reserved
08/15/2026 +0 days VulDB entry created
08/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74549 (🔒)
GCVE (CVE): GCVE-0-2026-74549
GCVE (VulDB): GCVE-100-390864
EUVD: 🔒

Entryinfo

Created: 08/15/2026 15:47
Updated: 08/15/2026 18:44
Changes: 08/15/2026 15:47 (60), 08/15/2026 18:44 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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