VulnerabilityPublished 15 Aug 2026Updated 6 Nov 2026

CVE-2026-74546: Linux kernel · hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in d328175045176f85c15c369bd21dc551351e7935 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 17:56 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in d328175045176f85c15c369bd21dc551351e7935, 832069bec79cf6f903441c5769d3cdba95d0af33, 76963b04b2d1c648d69949d8dd521e1ff7f40b51 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ fc958a61ff6d34a0ec42744d3ff524ee202b2e9f, < d328175045176f85c15c369bd21dc551351e7935	Fixed in d328175045176f85c15c369bd21dc551351e7935
LinuxLinux	Affected ≥ fc958a61ff6d34a0ec42744d3ff524ee202b2e9f, < 832069bec79cf6f903441c5769d3cdba95d0af33	Fixed in 832069bec79cf6f903441c5769d3cdba95d0af33
LinuxLinux	Affected ≥ fc958a61ff6d34a0ec42744d3ff524ee202b2e9f, < 76963b04b2d1c648d69949d8dd521e1ff7f40b51	Fixed in 76963b04b2d1c648d69949d8dd521e1ff7f40b51
LinuxLinux	Affected ≥ fc958a61ff6d34a0ec42744d3ff524ee202b2e9f, < 009240d057e26831cc925feaba4c490209c1d0ba	Fixed in 009240d057e26831cc925feaba4c490209c1d0ba
LinuxLinux	Affected ≥ fc958a61ff6d34a0ec42744d3ff524ee202b2e9f, < 689a2ea75434131d0af58aeb7d51fde40e858b4d	Fixed in 689a2ea75434131d0af58aeb7d51fde40e858b4d
LinuxLinux	Affected ≥ fc958a61ff6d34a0ec42744d3ff524ee202b2e9f, < 96ad57d31763559d376416cdf3bf5ae79bbbebec	Fixed in 96ad57d31763559d376416cdf3bf5ae79bbbebec

AI-suggested

A fix is available and has been applied in multiple Linux kernel commits. Users running Linux kernel version 5.15 should update to a fixed version incorporating the referenced commits to remediate this issue.

Description

A time-of-check to time-of-use (TOCTOU) race condition in the Linux kernel's hwmon driver for adt7470 devices could cause a divide-by-zero crash when reading fan speed data. The issue occurs if the fan data changes to zero between validation and conversion, leading to a kernel crash. This vulnerability affects Linux kernel version 5.15 and has been fixed by modifying the code to read the fan data once, preventing the race condition.

Impact

Exploitation of this vulnerability can cause a kernel crash (denial of service) due to a divide-by-zero error in the hardware monitoring driver. There is no indication of privilege escalation or data corruption beyond the crash. No known exploits are reported in the wild.

Summary

CVE-2026-74546 addresses a TOCTOU vulnerability in the Linux kernel's hwmon driver for adt7470 hardware monitoring. The flaw arises when the fan speed data becomes zero after the FAN_DATA_VALID() check but before the FAN_PERIOD_TO_RPM() calculation, causing a divide-by-zero error and kernel crash due to a race condition with concurrent updates of the cached fan value. The fix involves reading the fan data a single time to eliminate the race condition.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 17:56 UTC

Technical details

References

Community reviews

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