CVE-2026-53344 pinctrl: mcp23s08: Initialize mcp->dev and mcp->addr before regmap init
A null pointer dereference in the MCP23S08 pinctrl driver causes a kernel crash during device probe, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53344?
CVE-2026-53344 is a medium-severity vulnerability in Linux kernel, published on 1 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-908
Which versions are affected by CVE-2026-53344?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53344?
Apply the vendor's patch.
Is CVE-2026-53344 being exploited?
There is no known exploitation of CVE-2026-53344 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2026-53344, GHSA-7638-fmxx-mr26, UBUNTU-CVE-2026-53344.