CVE-2026-43067: Linux kernel · ext4: handle wraparound when searching for blocks for indirect mapped blocks
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 28 Oct 2026, 11:33 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 5 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 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-gcp-6.11pkg:deb/ubuntu/linux-gcp-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-gcp-6.14pkg:deb/ubuntu/linux-gcp-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-hwe-6.11pkg:deb/ubuntu/linux-hwe-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-hwe-6.14pkg:deb/ubuntu/linux-hwe-6.14?arch=source&distro=nobleOther 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 that adds a safety clamp in the ext4_mb_scan_groups() function to prevent allocation beyond the 32-bit block limit. Users should apply the updated Linux kernel versions that include this patch. The affected versions are explicitly listed and should be upgraded to a fixed version once available. No indication of temporary workarounds or no-action advisories is provided.
Description
CVE-2026-43067 is a critical vulnerability in the Linux kernel's ext4 filesystem handling. It involves improper handling of wraparound when searching for blocks for indirect mapped blocks, potentially allowing allocation of blocks beyond the intended 32-bit limit. This issue arises due to a logic flaw in the ext4_mb_scan_groups() function when backporting a commit intended to restrict block allocation. The vulnerability affects multiple specific Linux kernel versions and has a CVSS score of 9.8, indicating high severity.