CVE-2026-6386

medium

Published 2026-04-22 · Modified 2026-05-01

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CVSS v3

6.2

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

CVSS v4 NEW

—

not yet in upstream

VIR risk

6.2

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.

Predictions

Exploit likelihood

62%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

OS	Version	Status
freebsd	13.5	affected
freebsd	14.3	affected
freebsd	14.4	affected
freebsd	15.0	affected

References

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

CWEs

CWE-269 CWE-732

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.