CVE-2026-43404: Linux kernel · mm: Fix a hmm_range_fault() livelock / starvation problem
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.09% chance of exploitation in 30 days – higher than 0% 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 has been implemented and backported to affected Linux kernel versions. Users should update to the patched kernel versions listed or later. Since this is a kernel-level fix, applying the official kernel updates from the vendor or distribution is the recommended remediation. No additional mitigation is required beyond applying these updates.
Description
A livelock and starvation vulnerability in the Linux kernel's hmm_range_fault() function was resolved. The issue occurs when hmm_range_fault() fails to acquire a folio lock during page migration and spins waiting for the lock, potentially starving a work item scheduled on the same CPU. This can lead to an unresolved livelock condition under specific conditions involving device-private folios and system memory folios. The fix involves waiting for the folio to be unlocked instead of spinning. The vulnerability has a medium severity with no confidentiality or integrity impact but can cause availability issues.
References
- ubuntu.com/security/CVE-2026-43404 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43404 (opens in a new tab)
- git.kernel.org/linus/b570f37a2ce480be26c665345c5514686a8a0274 (opens in a new tab)
- git.kernel.org/stable/c/7e6e2fc91d4b9b12ec6e137019532568ebcf2680 (opens in a new tab)
- git.kernel.org/stable/c/94b6d0ba4b640ba23bb6c708a59316e74e5ede63 (opens in a new tab)
- git.kernel.org/stable/c/b570f37a2ce480be26c665345c5514686a8a0274 (opens in a new tab)