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MEDIUM · 6.2

CVE-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 prese...

Vulnerability Description

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.

CVSS Score

6.2

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE

Affected Products

VendorProductVersions
FreebsdFreebsd13.5

Related Weaknesses (CWE)

CWE-732CWE-269

References

FAQ

What is CVE-2026-6386?

CVE-2026-6386 is a vulnerability with a CVSS score of 6.2 (MEDIUM). 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 prese...

How severe is CVE-2026-6386?

CVE-2026-6386 has been rated MEDIUM with a CVSS base score of 6.2/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-6386?

Check the references section above for vendor advisories and patch information. Affected products include: Freebsd Freebsd.