Linux KernelOperating system · Linux

CVE-2026-53344

MEDIUM · 5.5 CVSS v3.1 Published 2026-07-01

Fix available

A fix is available. Upgrade to 7.0.13 or later.

See remediation →

57/100

Remediation priority · Elevated

Zero-click 7 weeks old

Official description

NVD · unedited

In the Linux kernel, the following vulnerability has been resolved: pinctrl: mcp23s08: Initialize mcp->dev and mcp->addr before regmap init Regmap initialization triggers regcache_maple_populate() which attempts SPI read to populate cache. SPI read requires mcp->dev and mcp->addr to be set, without them, NULL pointer dereference occurs during probe. Move initialization before mcp23s08_spi_regmap_init() call.

Technical summary

dbcve analysis · high confidence

In the Linux kernel pinctrl mcp23s08 driver, a NULL pointer dereference occurs during probe because regmap initialization triggers regcache_maple_populate() which performs an SPI read to populate its cache. This SPI read requires mcp->dev and mcp->addr to already be set, but they were initialized after the regmap init call, causing the dereference.

MitigationThe fix requires reordering initialization to set mcp->dev and mcp->addr before calling mcp23s08_spi_regmap_init(). This is a kernel driver code change requiring the Linux kernel source and rebuild of the affected module.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

Linux KernelOperating system

Affected:>= 6.19, < 7.0.13= 7.1

CVSS breakdown

From the vector

Attack vector: Local
Complexity: Low
Privileges: Low
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected?

dbcve checks

Work through these to decide whether this CVE applies to you.

Check kernel version

Run `uname -r` or check `/proc/version` to get the running kernel version

Affected if Kernel version is >= 6.19 AND < 7.0.13, OR equals 7.1
Identify MCP23S08 GPIO expander hardware

Check for the device in the system: look for SPI device enumeration in `/sys/bus/spi/devices/` or check `lsmod` for mcp23s08 module, or inspect dmesg for 'mcp23s08' or 'gpio-expander' messages

Affected if The system has a Microchip MCP23S08 or MCP23S17 SPI GPIO expander connected and the driver is loaded
Confirm SPI interface usage

Check if the MCP23S08 is accessed via SPI (the bug is in the SPI regmap init function, not I2C). Review system device tree or board configuration files for SPI connection details

Affected if The GPIO expander is connected via SPI bus rather than I2C; the bug affects mcp23s08_spi_regmap_init() specifically
Verify driver code has the fix

Inspect the driver source file (typically in drivers/pinctrl/pinctrl-mcp23s08.c or drivers/gpio/gpio-mcp23s08.c) and check if mcp->dev and mcp->addr are initialized BEFORE the call to mcp23s08_spi_regmap_init() in the probe function

Affected if The driver's probe function still shows mcp23s08_spi_regmap_init() called before mcp->dev and mcp->addr are set, indicating the unpatched code

A system is affected if it runs a vulnerable kernel version (>=6.19 to <7.0.13 or 7.1) AND has a Microchip MCP23S08 GPIO expander connected via SPI, with the driver using the unpatched code where initialization order is incorrect.

Generated from the published advisory. Verify against your own configuration.

Remediation

From vendor data

Upgrade available Upgrade to 7.0.13 or later

Fixed in 7.0.13

Interim mitigation

The fix requires reordering initialization to set mcp->dev and mcp->addr before calling mcp23s08_spi_regmap_init(). This is a kernel driver code change requiring the Linux kernel source and rebuild of the affected module.

Fix this in Linux Kernel Scoped from the published advisory

Consultation2.0 h
Implementation1.0 h
Testing3.0 h
Review / QA1.0 h

7.0 hours of engineering $1,210

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References

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53344 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2026-53344?

The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.

The version that genuinely resolved it — not the one the vendor claimed
A config change or rule that shut the vector down
A gotcha in the upgrade path that cost you an afternoon

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here

Verified mitigations, workarounds, and config changes
Version or environment caveats, and links to real fixes
No weaponised exploit code, or anything meant to cause harm
No spam, self-promotion, credentials, or personal data

At a glance

A fix existsUpgrade to 7.0.13 or later

Severity 5.5 Medium

Exploit likelihood EPSS, next 30 days 0.1%

Affects: Linux Kernel

Remediation

Need this fixed?

Fix this in Linux Kernel 7 hrs · Moderate

Typical engagement from $1,210

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Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

Check your environment

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References