CVE-2026-98262: Linux kernel · ata: libahci: clear PxCLBU and PxFBU for AHCI_HFLAG_32BIT_ONLY
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 28 Oct 2026, 01:27 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 6 Oct 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.
Description
In the Linux kernel, the following vulnerability has been resolved: ata: libahci: clear PxCLBU and PxFBU for AHCI_HFLAG_32BIT_ONLY A user reported that commit 105c42566a55 ("ata: ahci: force 32-bit DMA for JMicron JMB582/JMB585") made the JMicron JMB585 unusable on his board. The failure is seen as soon as the ahci driver is probed, and booting with iommu=off does not solve the problem. Looking at the AHCI specification, PxCLBU and PxFBU are both read only '0' for HBAs that do not support 64-bit addressing. For HBAs that do support 64-bit addressing, the registers are read write, with a reset value that is Implementation Specific. When using the AHCI_HFLAG_32BIT_ONLY flag, the HBA does support 64-bit addressing, and a 32-bit DMA mask is set by simply clearing HOST_CAP_64. Thus, in this case, we need to explicitly clear the registers to 0.
References
- ubuntu.com/security/CVE-2026-98262 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98262 (opens in a new tab)
- git.kernel.org/linus/82e47533221d4746947b74d2e79a478c36c6433a (opens in a new tab)
- git.kernel.org/stable/c/0191c9ff23ef1678dbfb5ad253a2dee92feb5d71 (opens in a new tab)
- git.kernel.org/stable/c/4719424bb7cb9f20b73986bcb72dd528f0e5c6eb (opens in a new tab)
- git.kernel.org/stable/c/7912ad8fb5233bb8cfe21d50df639c7f4854ff9d (opens in a new tab)
- git.kernel.org/stable/c/82e47533221d4746947b74d2e79a478c36c6433a (opens in a new tab)
- git.kernel.org/stable/c/8f510f68208a1f673d7c7234a687be4671490e9c (opens in a new tab)
- git.kernel.org/stable/c/a5a8b4737f68bbac8aa0685af0c8921e6003c22b (opens in a new tab)
- git.kernel.org/stable/c/b28a17d4a9bb0aa38b48681c3927b012ba40eabe (opens in a new tab)
- git.kernel.org/stable/c/b691a3e244278362e552439d6d3ee5a5d3703488 (opens in a new tab)