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

6.2 / 10

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

Basic Information

ID CVE-2026-6386

Source freebsd

Published Apr 22, 2026 at 02:33

Modified Apr 22, 2026 at 14:32

Affected Product

Vendor FreeBSD

Product FreeBSD

Version 15.0-RELEASE

Affected Versions FreeBSD FreeBSD 15.0-RELEASE
FreeBSD FreeBSD 14.4-RELEASE
FreeBSD FreeBSD 14.3-RELEASE
FreeBSD FreeBSD 13.5-RELEASE

CWE Classification

CWE-269 CWE-732

References

security.freebsd.org /advisories/FreeBSD-SA-26:11.amd64.asc

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    "published": "2026-04-22T02:33:24.846Z",
    "modified": "2026-04-22T14:32:53.989Z",
    "type": "cve",
    "title": "Missing large page handling in pmap_pkru_update_range()",
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