User-Space System Call Vulnerability in Zephyr Logging Subsystem

CVE-2026-12364

What is CVE-2026-12364?

The Zephyr logging subsystem contains a vulnerability in the user-space system-call verifier, specifically in the function z_vrfy_z_log_msg_static_create(). This function improperly forwards user-supplied arguments directly to kernel-mode functions without the necessary security checks. As a result, unprivileged user-mode threads can manipulate these arguments, leading to arbitrary kernel memory reading and potential denial of service. Attackers may exploit this flaw to gain sensitive information from kernel memory or to disrupt system functionality. The recent patch has introduced stringent validations to mitigate these risks, ensuring that out-of-bounds accesses are dealt with appropriately, thereby preserving the integrity of the system.

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