CVE-2026-89456: Linux kernel · s390/dasd: Propagate partial completion length across ERP recovery
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.0 High.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation 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
A fix for this vulnerability has been implemented in the Linux kernel. Users should apply the official kernel update that includes this patch to ensure proper handling of partial completion lengths during ERP recovery. No additional mitigation steps are indicated.
Description
In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Propagate partial completion length across ERP recovery dasd_default_erp_postaction() copies the timing and device state from the finished ERP request back to the original request but drops proc_bytes. A request that was partially completed, an ESE read of a not-yet-allocated track returns fewer bytes than requested, and then recovered through the ERP chain loses its partial-completion length. __dasd_cleanup_cqr() then sees proc_bytes == 0 and completes the whole request instead of requeueing the remainder, silently returning zeroed data for the part that was never read. Carry proc_bytes over to the original request like the other per-request state.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89456 (opens in a new tab)
- git.kernel.org/stable/c/15ec03452c18e8d288e519837d21b308300d74b2 (opens in a new tab)
- git.kernel.org/stable/c/6fb5ba2e7e43173a3761e46f091070a8185efa14 (opens in a new tab)
- git.kernel.org/stable/c/ceafb262475ac6cb3a7d07b1102608be2b216b99 (opens in a new tab)
- git.kernel.org/stable/c/d6b8778b1b82aa3a8dbf8612080f635b834bd16b (opens in a new tab)
- ubuntu.com/security/CVE-2026-89456 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89456 (opens in a new tab)
- git.kernel.org/linus/6fb5ba2e7e43173a3761e46f091070a8185efa14 (opens in a new tab)