Log in Start free

Vulnerability · Published Sep 11, 2026 · Assigned by Linux

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

High 7.1

In plain English

A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.1High
Exploit odds (30 days)0.1%top 97.7% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13linux6.12.111-1DEBIAN-CVE-2026-89593
Debian:14linux7.2.6-1DEBIAN-CVE-2026-89593
Debian:12linux-6.126.12.111-1~deb12u1DEBIAN-CVE-2026-89593
Ubuntu:26.04:LTSlinux7.0.0-42.42UBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-aws7.0.0-1016.17UBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-aws-7.0no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-azure-7.0no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-azure-fde-7.0no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-gcp7.0.0-1016.18UBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-gcp-7.0no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-42.42~24.04.1UBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-ibm7.0.0-1017.17UBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-nvidia-7.0no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-nvidia-bosno fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1017.17UBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-oracle7.0.0-1015.16UBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-oracle-7.0no fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-89593
Ubuntu:26.04:LTSlinux-riscv7.0.0-42.42.1UBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-89593
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-42.42.1~24.04.1UBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-89593
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-89593

Affected products (as reported)

VendorProductVersions
Linux Linux df7a6d1f64056aec572162c5d35ed9ff86ece6f3 – before b0b1b9ca80b795ed2223e76dd787db7067121fb9df7a6d1f64056aec572162c5d35ed9ff86ece6f3 – before a3c65af20cceb7f997847727636b4017326f845ddf7a6d1f64056aec572162c5d35ed9ff86ece6f3 – before 0f001491e5a2ec69aa9d5dd6b799e5742245f9eadf7a6d1f64056aec572162c5d35ed9ff86ece6f3 – before 5120b1e048d48596ffaec1a8412012a91adba73b
Linux Linux 6.9

References