CVE-2026-6386
In order to apply a particular protection key to an address range, the kernel must update the corresponding page table entries.
Published Apr 22, 2026 · updated Jun 17, 2026 · freebsd freebsd
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 shm_create_largepage(3) interface. In particular, it would always treat a page directory page entry as pointing to another page table page. The bug can be abused by an unprivileged user to cause pmap_pkru_update_range() to treat userspace memory as a page table page, and thus overwrite memory to which the application would otherwise not have access.
Code
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Timeline
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Apr 22, 2026 · NIST NVD
Detected
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 shm_create_largepage(3) interface. In particular, it would always treat a page directory page entry as pointing to another page table page. The bug can b
Jun 17, 2026 · NIST NVD
Updated
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 shm_create_largepage(3) interface. In particular, it would always treat a page directory page entry as pointing to another page table page. The bug can b
Affected
- cpe freebsd/freebsd13.5
Sources
- CVE.orgVulnerability recordCVE-2026-6386
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-6386
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 shm_create_largepage(3) interfac
nvd.nist.gov