CVE-2026-43286: Linux kernel · mm/hugetlb: restore failed global reservations to subpool
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability has been implemented in the Linux kernel. Users should apply the updated kernel versions that include the patch for CVE-2026-43286 to resolve the subpool accounting issue. Since this is a kernel-level fix, upgrading to a patched kernel version is the recommended remediation. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's hugetlb subsystem causes the subpool's used hugepage counter to be incorrectly incremented on failed global page allocation attempts. This leads to the subpool eventually becoming unusable as its used counter reaches the maximum limit, preventing further hugepage allocations despite no actual consumption. The issue was introduced as a side effect of a previous fix addressing an underflow error in global reservations accounting.
References
- ubuntu.com/security/CVE-2026-43286 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43286 (opens in a new tab)
- git.kernel.org/linus/1d3f9bb4c8af70304d19c22e30f5d16a2d589bb5 (opens in a new tab)
- git.kernel.org/stable/c/1d3f9bb4c8af70304d19c22e30f5d16a2d589bb5 (opens in a new tab)
- git.kernel.org/stable/c/5eac1322a7b14b8cd05ec896618278b90fba7f39 (opens in a new tab)
- git.kernel.org/stable/c/f055897c975d079a90af873c791ab58cf0f6f2a5 (opens in a new tab)