CVE-2026-74546

Received Received - Intake

Divide-by-zero TOCTOU in Linux Kernel hwmon adt7470

Publication date: 2026-08-15

Last updated on: 2026-08-19

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read If the fan data becomes 0 between the FAN_DATA_VALID() check and the FAN_PERIOD_TO_RPM() conversion, it will result in a divide-by-zero crash due to a race with a concurrent update of the cached fan value. Fix a TOCTOU issue by reading fan data once.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-19

Generated

2026-09-05

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74546

EUVD

EUVD-2026-59739

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability is a divide-by-zero race condition in the Linux kernel's hwmon subsystem, specifically affecting the adt7470 driver. It occurs when fan data temporarily becomes zero between a validity check and a conversion to RPM, causing a crash due to division by zero.

Detection Guidance

This vulnerability is specific to the Linux kernel's hwmon subsystem (adt7470 driver) and may not have direct network detection methods. Monitor kernel logs for divide-by-zero errors or crashes related to fan speed readings. Check for kernel oops messages or system crashes during high fan activity changes.

Impact Analysis

If exploited, this vulnerability could crash the system by triggering a divide-by-zero error during fan speed monitoring. This may lead to denial-of-service conditions, system instability, or potential data loss if critical processes are interrupted.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it is a technical flaw in the Linux kernel's hwmon subsystem. It may indirectly impact compliance if the crash leads to system unavailability or data corruption, but no specific regulatory impact is mentioned in the provided context.

Mitigation Strategies

Update your Linux kernel to the latest patched version that includes the fix for CVE-2026-74546. If immediate patching is not possible, consider disabling the adt7470 driver if fan monitoring is not critical. Monitor system logs for signs of exploitation or crashes.

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