CVE-2026-90104: Linux kernel · NFSv4.1: zero referring call lists before decoding
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 50% 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:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 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 is available that changes the memory allocation method to zero-initialize the referring call lists, preventing use of uninitialized pointers. Users should apply the official Linux kernel patches that address this issue. Since this is a kernel vulnerability, updating to a patched kernel version is the recommended remediation. Patch status is not explicitly confirmed in the input data; check the vendor advisory for current remediation guidance.
Description
A vulnerability in the Linux kernel's NFSv4.1 implementation involves uninitialized memory usage in the handling of referring call lists. Specifically, decode_cb_sequence_args() allocates memory without zeroing it, leading to potential use of stale data when freeing memory. This flaw has been resolved by changing the allocation to zero-initialize the memory, preventing stale pointer dereferences.
References
- nvd.nist.gov/vuln/detail/CVE-2026-90104 (opens in a new tab)
- git.kernel.org/stable/c/8fa4804fe62ca4155a2d8fc2789d630376cbf2fc (opens in a new tab)
- git.kernel.org/stable/c/f31f3c042e024aef437cda42f0424ae8d4594b6c (opens in a new tab)
- ubuntu.com/security/CVE-2026-90104 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-90104 (opens in a new tab)
- git.kernel.org/linus/8fa4804fe62ca4155a2d8fc2789d630376cbf2fc (opens in a new tab)