Kernel Memory Management Issue in FreeBSD Affects Unprivileged Users

CVE-2026-6386

What is CVE-2026-6386?

A vulnerability in the FreeBSD kernel arises from a failure in the page table update mechanism, specifically when applying protection keys to address ranges. This flaw neglects the presence of 1GB largepage mappings created via the shm_create_largepage(3) interface, leading to a situation where the system improperly interprets a page directory entry. Consequently, unprivileged users may exploit this bug to manipulate memory allocations, enabling access to memory regions outside of their permissions, thus compromising the integrity of user-space applications.

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