CVE-2026-97591: Linux kernel · s390/crypto: Fix handling of EBUSY in PHMAC when req is pushed to crypto engine
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 25 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 has been implemented in the Linux kernel to correctly handle the EBUSY return code in the s390 crypto PHMAC implementation. Users should apply the updated kernel versions that include this fix. Patch status is confirmed by the resolution note; no additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's s390 crypto subsystem related to the handling of EBUSY return codes in PHMAC when requests are pushed to the crypto engine has been resolved. The issue was that the EBUSY return code was not correctly handled as a successful transfer indication, which has now been fixed.
References
- ubuntu.com/security/CVE-2026-97591 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-97591 (opens in a new tab)
- git.kernel.org/stable/c/bcd7f1f1e2f2882ad206f72425255be105178151 (opens in a new tab)
- git.kernel.org/stable/c/330148371401de474b656eaf521861f12ec1a1ce (opens in a new tab)
- git.kernel.org/stable/c/203702f0013f9b7324e8c5facb6cd6e9c0942b13 (opens in a new tab)