CVE-2026-74738

Local system crash via unset callback dereference

Published Aug 26, 2026 · Updated Aug 26, 2026

NULL pointer dereference in the regmap SoundWire MBQ component in Linux allows local users to crash the system via a device response. The regmap_sdw_mbq_poll_busy() function calls an optional readable_reg callback without checking whether it is set after a COMMAND_IGNORED response produces -ENODATA. Exploitation requires an MBQ regmap lacking that callback and a SoundWire device returning COMMAND_IGNORED; the resulting kernel fault interrupts the system.

CVSS severity5.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the regmap SoundWire MBQ component in Linux allows local users to crash the system via a device response. The regmap_sdw_mbq_poll_busy() function calls an optional readable_reg callback without checking whether it is set after a COMMAND_IGNORED response produces -ENODATA. Exploitation requires an MBQ regmap lacking that callback and a SoundWire device returning COMMAND_IGNORED; the resulting kernel fault interrupts the system.

The record

CVE
CVE-2026-74738
Published
Aug 26, 2026
Updated
Aug 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 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=5bc493bf0c37c157bf2eb364e55a1c6f8bc43a69 <00268f9452d2a0d660aa9c1bb0ca07a994af6a4f
  2. Affected versionversion=5bc493bf0c37c157bf2eb364e55a1c6f8bc43a69 <5bd8e897ecf558507142f4553e4526adfc1d6482
  3. Affected versionversion=5bc493bf0c37c157bf2eb364e55a1c6f8bc43a69 <6cf600b276a55a6481462830607a611f32e737c0
  4. Affected versionversion=6.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5bc493bf0c37c157bf2eb364e55a1c6f8bc43a69 <00268f9452d2a0d660aa9c1bb0ca07a994af6a4f; version=5bc493bf0c37c157bf2eb364e55a1c6f8bc43a69 <5bd8e897ecf558507142f4553e4526adfc1d6482; version=5bc493bf0c37c157bf2eb364e55a1c6f8bc43a69 <6cf600b276a55a6481462830607a611f32e737c0; version=6.14

Published CVSS scores

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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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