CVE-2026-74733

Service disruption via unlocked GPIO register access

Published Aug 22, 2026 · Updated Aug 25, 2026

Race condition in the Linux pca953x GPIO driver allows local users to disrupt GPIO operations through concurrent register access. The pca953x_irq_bus_sync_unlock function reads the direction register without holding i2c_lock even though regmap locking is disabled. Exploitation requires concurrent interrupt updates on a system using a PCA953x GPIO expander; incorrect reads or writes can corrupt GPIO state or crash the system.

CVSS severity7.8
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux pca953x GPIO driver allows local users to disrupt GPIO operations through concurrent register access. The pca953x_irq_bus_sync_unlock function reads the direction register without holding i2c_lock even though regmap locking is disabled. Exploitation requires concurrent interrupt updates on a system using a PCA953x GPIO expander; incorrect reads or writes can corrupt GPIO state or crash the system.

The record

CVE
CVE-2026-74733
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-413, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=58a5c93bd1a6e949267400080f07e57ffe05ec34
  2. Affected versionversion=6.10
  3. Affected versionversion=6.1.101 <6.2
  4. Affected versionversion=6.6.42 <6.7
  5. Affected versionversion=6.9.11 <6.10
  6. Affected versionversion=bfc6444b57dc7186b6acc964705d7516cbaf3904 <9dc325327babe7f159e84cbe9380a45342da0585
  7. Affected versionversion=bfc6444b57dc7186b6acc964705d7516cbaf3904 <e6a2f5f845f50b0c4299bace5111f56d3390a090
  8. Affected versionversion=de7cffa53149c7b48bd1bb29b02390c9f05b7f41
  9. Affected versionversion=e2ecdddca80dd845df42376e4b0197fe97018ba2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=58a5c93bd1a6e949267400080f07e57ffe05ec34; version=6.10; version=6.1.101 <6.2; version=6.6.42 <6.7; version=6.9.11 <6.10; version=bfc6444b57dc7186b6acc964705d7516cbaf3904 <9dc325327babe7f159e84cbe9380a45342da0585; version=bfc6444b57dc7186b6acc964705d7516cbaf3904 <e6a2f5f845f50b0c4299bace5111f56d3390a090; version=de7cffa53149c7b48bd1bb29b02390c9f05b7f41; version=e2ecdddca80dd845df42376e4b0197fe97018ba2

Published CVSS scores

7.8CVE.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-413Improper Resource Locking
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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