CVE-2026-89568: Linux kernel · kho: fix size calculation in kho_preserved_memory_reserve()
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 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 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 is available that corrects the size calculation by using an unsigned long integer for the shift operation in kho_preserved_memory_reserve(). Users should update to patched Linux kernel versions that include this fix. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's kho_preserved_memory_reserve() function causes incorrect size calculation for memory preservations larger than 2 GiB due to a 32-bit integer shift limitation. This can lead to undefined behavior when handling large memory reservations. The issue affects specific Linux kernel versions and has been fixed by changing the shift operation to use an unsigned long integer.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89568 (opens in a new tab)
- git.kernel.org/stable/c/3a0b8fa2eb36afc88b62a95f33f0c77c71fa5ded (opens in a new tab)
- git.kernel.org/stable/c/42a6f03cf352eb6e6dbeef95e75e686f4cdb9bd1 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89568 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89568 (opens in a new tab)
- git.kernel.org/linus/3a0b8fa2eb36afc88b62a95f33f0c77c71fa5ded (opens in a new tab)