CVE-2026-43288: Linux kernel · ext4: move ext4_percpu_param_init() before ext4_mb_init()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1060.63~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1060.63~22.04.1, 6.8.0-1063.71~22.04.1, 6.8.0-1062.69~22.04.1 +30
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
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?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 patch is available that fixes the issue by reordering initialization calls in the ext4 filesystem code. Users should apply the official Linux kernel updates provided by their distribution, such as the Ubuntu security notice USN-8492-1. No additional mitigation is required beyond applying the update.
Description
A vulnerability in the Linux kernel's ext4 filesystem code could cause a kernel panic due to uninitialized per-CPU counters during block bitmap validation. This issue occurs when ext4_percpu_param_init() is called after ext4_mb_init(), leading to a panic when the corrupted block bitmap is detected. The flaw has been fixed by reordering the initialization sequence to ensure per-CPU counters are set up before use.
References
- ubuntu.com/security/CVE-2026-43288 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43288 (opens in a new tab)
- git.kernel.org/linus/270564513489d98b721a1e4a10017978d5213bff (opens in a new tab)
- git.kernel.org/stable/c/0d5fcb063cdabb9aeaa8554b7fedad2092c4150e (opens in a new tab)
- git.kernel.org/stable/c/270564513489d98b721a1e4a10017978d5213bff (opens in a new tab)
- git.kernel.org/stable/c/9e9fb259bcddf459a0168f4a964e979e500a68a5 (opens in a new tab)
- git.kernel.org/stable/c/aec095f3cc6cf209effd93278ce35be27db81d73 (opens in a new tab)
- git.kernel.org/stable/c/bf5b609524497c195f801cd5707252384aed8149 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8497-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8498-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8499-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8607-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8609-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8619-1 (opens in a new tab)