CVE-2026-68453: Linux kernel · s390/zcrypt: Fix buffer over-read in cca_cipher2protkey
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.1 High : upgrade to 6.8.0-1036.39 soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1036.39
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Aug 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 the Ubuntu linux-nvidia-tegra package to 6.8.0-1036.39.
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 patch is available and should be applied to affected Linux kernel versions. The Ubuntu advisory USN-8886-1 confirms fixes in multiple kernel subsystems including s390/zcrypt. Users should update to the fixed kernel versions as listed in the vendor advisory and reboot the system. No additional mitigations are required beyond applying the official updates.
Description
A vulnerability in the Linux kernel's s390/zcrypt subsystem allowed buffer over-read and underflow due to improper validation of user-controlled length fields in cryptographic token structures. This flaw could lead to kernel crashes or exposure of memory when processing specially crafted requests. The issue has been fixed by adding validation checks on buffer sizes and token length fields. Multiple specific Linux kernel versions are affected.
References
- nvd.nist.gov/vuln/detail/CVE-2026-68453 (opens in a new tab)
- git.kernel.org/stable/c/36b230835b8a008266aad22168ca52afacc8a58d (opens in a new tab)
- git.kernel.org/stable/c/3b2abee2a678607ae27975bc6833785c2002df43 (opens in a new tab)
- git.kernel.org/stable/c/a57fd7fcdb63e2d5ceac78bbe825ec986062a9da (opens in a new tab)
- ubuntu.com/security/CVE-2026-68453 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-68453 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)