CVE-2026-6386 (GCVE-0-2026-6386)

Vulnerability from cvelistv5 – Published: 2026-04-22 02:33 – Updated: 2026-04-22 14:32
VLAI?
Title
Missing large page handling in pmap_pkru_update_range()
Summary
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.
Severity ?
6.2 (Medium)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE
  • CWE-269 - Improper Privilege Management
  • CWE-732 - Incorrect Permission Assignment for Critical Resource
Assigner
References
Impacted products
Vendor Product Version
FreeBSD FreeBSD Affected: 15.0-RELEASE , < p6 (release)
Affected: 14.4-RELEASE , < p2 (release)
Affected: 14.3-RELEASE , < p11 (release)
Affected: 13.5-RELEASE , < p12 (release)
Create a notification for this product.
Date Public ?
2026-04-21 18:00
Credits
Nicholas Carlini using Claude, Anthropic
Show details on NVD website
To clipboard 

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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