CVE-2026-46326: Linux Kernel MPRLS0025PA Pressure Sensor Driver Memory Initialization Flaw

Technical summary

CVE-2026-46326 is a memory initialization vulnerability in drivers/iio/pressure/mprls0025pa.c within the Linux kernel. The vulnerability stems from improper initialization of an spi_transfer structure used for SPI (Serial Peripheral Interface) communication with the pressure sensor. Without explicit zeroing, the structure may retain kernel stack memory containing sensitive data or unintended values. An unprivileged local process can trigger sensor read operations that expose this uninitialized memory or cause kernel memory corruption. The fix requires zeroing the spi_transfer struct prior to population and use.

Business impact

Organizations deploying Linux-based embedded systems, IoT devices, or edge computing platforms that incorporate MPRLS0025PA pressure sensors face heightened risk of local privilege escalation and information disclosure. The HIGH severity rating reflects the potential for attackers to gain complete system compromise on affected devices. In industrial and critical infrastructure environments where these sensors are used (e.g., HVAC monitoring, pressure measurement systems), exploitation could lead to unauthorized access, data theft, or system tampering.

Affected systems

Linux kernel installations that include the mprls0025pa IIO pressure driver. This affects kernel versions prior to the patch; verify against vendor advisories for specific affected versions. Systems are at risk only if: (1) the mprls0025pa driver is compiled in or loaded as a module, and (2) an unprivileged local user can access the sensor via the IIO interface. Embedded Linux distributions, specialized IoT platforms, and custom kernel builds for industrial measurement systems are primary targets.

Exploitability

Local exploitability is straightforward: no network access required, no user interaction needed, and no elevated privileges required to trigger the vulnerability. An attacker needs only local shell access and the ability to interact with the IIO sensor device interface. The attack surface is local-only, limiting internet-facing risk, but the ease of exploitation once on the system is significant. Exploitation could yield kernel memory leaks, kernel state modification, or denial of service depending on memory layout and usage patterns.

Remediation

Apply the kernel patch that properly initializes the spi_transfer struct via memset or designated initializers (e.g., {0}). This ensures the structure contains only zeroed memory before the SPI communication fields are populated. Verify the patch against your kernel version and distribution's security advisories. Recompile and deploy the patched kernel to all affected systems. For systems where recompilation is not feasible, disable or remove the mprls0025pa driver if it is not in active use.

Patch guidance

Check your Linux distribution and kernel version against available security advisories from kernel.org, your distributor's security portal, and the mprls0025pa driver maintainers. Patches are typically delivered through standard kernel security updates. After patching, validate that the spi_transfer struct initialization now explicitly zeros memory before use. Test the driver functionality post-patch to ensure sensor communication remains stable. For production embedded systems, follow your organization's change management and testing procedures before deployment.

Detection guidance

Monitor kernel logs for IIO pressure sensor driver errors or crashes that could indicate exploitation attempts. Audit file access to /sys/bus/iio/devices/ and sensor read operations from unprivileged processes. Use kernel security tools (AppArmor, SELinux) to restrict unprivileged access to IIO sensor interfaces if not required. Intrusion detection systems should flag unusual reads of sensor data or kernel error messages tied to the mprls0025pa driver. Host-based security software should monitor for processes attempting to access device memory or trigger sensor operations in suspicious patterns.

Why prioritize this

HIGH severity (CVSS 8.4) combined with ease of local exploitation and potential for privilege escalation and information disclosure warrants urgent attention. Although the vulnerability requires local access, the lack of authentication or complex steps to trigger it makes it a critical priority for system hardening. Any internet-facing system with local user accounts, container escape routes, or SSH access faces meaningful risk.

Risk score, explained

The CVSS 3.1 score of 8.4 (HIGH) reflects: (1) local attack vector requiring no network; (2) low complexity—trivial to trigger once on the system; (3) no privileges or user interaction needed; (4) high confidentiality impact from kernel memory disclosure; (5) high integrity impact from potential kernel state corruption; and (6) high availability impact from possible denial of service. The score appropriately captures the severity of privilege escalation and information disclosure risks in kernel-level memory handling.

Frequently asked questions