CVE-2026-89457: Linux kernel · s390/dasd: Guard sysfs discipline callbacks against unallocated private data
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
- 0.1% 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 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
Until a fix is applied, avoid triggering the affected sysfs attributes during device online operations in the s390/dasd subsystem. Monitor vendor channels for official patches or updates.
Description
In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Guard sysfs discipline callbacks against unallocated private data Several sysfs show/store handlers call a discipline callback that dereferences device->private, either directly or through the DASD_DEFINE_ATTR() macro. During dasd_generic_set_online() the discipline is assigned before check_device() allocates device->private, so an unprivileged read of one of these world-readable attributes in that window dereferences a NULL pointer and panics. Guard the dereference inside each callback that actually touches device->private.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89457 (opens in a new tab)
- git.kernel.org/stable/c/2a1780f9fc2493bd34c418a0be6fc58943afcecf (opens in a new tab)
- git.kernel.org/stable/c/449f3bada7a9fad8b8cdf4bb20baf27ee9ca56c5 (opens in a new tab)
- git.kernel.org/stable/c/536407b272402af679155910d7fdeeb4834eefb9 (opens in a new tab)
- git.kernel.org/stable/c/6452c13646af7c13d7f6668b6690cfb2427e7f7b (opens in a new tab)
- ubuntu.com/security/CVE-2026-89457 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89457 (opens in a new tab)
- git.kernel.org/linus/2a1780f9fc2493bd34c418a0be6fc58943afcecf (opens in a new tab)