High 7.1Published Sep 11, 2026

CVE-2026-89593hugetlb: only adjust reservation during unmapping if mapcount is 0

Updated under an hour ago (2026-10-19 06:10 UTC)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: hugetlb: only adjust reservation during unmapping if mapcount is 0 Since df7a6d1f6405, __unmap_hugepage_range can adjust reservations. In the case of folio mapped in both a parent and a child, if the parent unmaps the range first, the reservation adjustment will result in an underflow of the reserved count. Once the child unmaps the range, the count is restored. Change __unmap_hugepage_range() to check the mapcount before adjusting the reservation.

CVSS: 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Received
Record last updated: Sep 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from df7a6d1f64056aec572162c5d35ed9ff86ece6f3 before b0b1b9ca80b795ed2223e76dd787db7067121fb9; from df7a6d1f64056aec572162c5d35ed9ff86ece6f3 before a3c65af20cceb7f997847727636b4017326f845d; from df7a6d1f64056aec572162c5d35ed9ff86ece6f3 before 0f001491e5a2ec69aa9d5dd6b799e5742245f9ea; from df7a6d1f64056aec572162c5d35ed9ff86ece6f3 before 5120b1e048d48596ffaec1a8412012a91adba73b	CNA record

References

https://git.kernel.org/stable/c/b0b1b9ca80b795ed2223e76dd787db7067121fb9
https://git.kernel.org/stable/c/a3c65af20cceb7f997847727636b4017326f845d
https://git.kernel.org/stable/c/0f001491e5a2ec69aa9d5dd6b799e5742245f9ea
https://git.kernel.org/stable/c/5120b1e048d48596ffaec1a8412012a91adba73b

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.