CVE-2026-93227: Linux kernel · mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 24 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 has been implemented to ensure that the update of pgdat->first_deferred_pfn does not overflow when the entire zone's memory map is initialized. Users should apply the official kernel updates that include this fix. Since this is a kernel-level issue, upgrading to a patched kernel version is the recommended remediation. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory for current remediation guidance.
Description
A vulnerability in the Linux kernel's memory initialization code (deferred_grow_zone) can cause an out-of-range update of the first_deferred_pfn pointer when CONFIG_DEFERRED_STRUCT_PAGE_INIT and CONFIG_CMA are enabled. This leads to a kernel panic due to a BUG_ON() triggered by accessing memory beyond the node's RAM end during boot. The issue occurs with large CMA reservations and unaligned node RAM ends on PAGES_PER_SECTION boundaries.
References
- ubuntu.com/security/CVE-2026-93227 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-93227 (opens in a new tab)
- git.kernel.org/stable/c/97090500d776c3f6d08e857e3a0a7cf092999094 (opens in a new tab)
- git.kernel.org/stable/c/45489d4f95802903ab35799b400b346fa4e13151 (opens in a new tab)
- git.kernel.org/stable/c/84339578c2d6936ac3a93cd1f0bbaa3468a988f2 (opens in a new tab)