CVE-2026-89684: Linux kernel · nfsd: fix cpntf publish race in nfs4_init_cp_state
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 updates that include this patch to the affected versions. Since this is a kernel-level fix, upgrading to a patched kernel version is the recommended remediation. No additional mitigations are indicated by the vendor advisory.
Description
A race condition vulnerability in the Linux kernel's NFS server (nfsd) related to the cpntf publish process in nfs4_init_cp_state and nfs4_alloc_init_cpntf_state() has been resolved. The flaw allowed a race between publishing a new cpntf entry and a concurrent OFFLOAD_CANCEL operation, which could cause a server crash (kernel oops) due to list manipulation on uninitialized data structures. This affects specific Linux kernel versions used in various Ubuntu releases.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89684 (opens in a new tab)
- git.kernel.org/stable/c/21d6c5957f5ca97d7352e60f55ea412beb9419f5 (opens in a new tab)
- git.kernel.org/stable/c/a631a26a8777bb235eabd478bbbaf26a4db750bf (opens in a new tab)
- git.kernel.org/stable/c/be3a5c1d857b0dcbc11796cea603ef25834f75b2 (opens in a new tab)
- git.kernel.org/stable/c/c7270f62e7a05a2ee68aa2b74262b658a14463bd (opens in a new tab)
- ubuntu.com/security/CVE-2026-89684 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89684 (opens in a new tab)
- git.kernel.org/linus/be3a5c1d857b0dcbc11796cea603ef25834f75b2 (opens in a new tab)