CVE-2026-6386

CVE-2026-6386: FreeBSD kernels with amd64 shmlargepage handling miss in pmap_pkru_update_range() fail to account for 1GB largepage mappings. An unprivileged user could cause the kernel to treat userspace memory as a page-table page, enabling overwrite of memory otherwise inaccessible. Impact desc...

CVE-2026-6386 Missing large page handling in pmap_pkru_update_range()

In order to apply a particular protection key to an address range, the kernel must update the corresponding page table entries. The subroutine which handled this failed to take into account the presence of 1GB largepage mappings created using the shmcreatelargepage3 interface. In particular, it...

FreeBSD : FreeBSD -- Missing large page handling in pmap_pkru_update_range() (128951d0-3df0-11f1-bb07-bc241121aa0a)

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 128951d0-3df0-11f1-bb07-bc241121aa0a advisory. In order to apply a particular protection key to an address range, the kernel must update the...