CVE-2026-89776: Linux kernel · vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributes
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
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 16 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 enforces exact length validation on GROUP/GROUP6 attributes in the VXLAN VNI filter entry policy. Users should update to patched kernel versions that include this fix. Since this is a kernel-level vulnerability, applying the official kernel updates from the vendor is the recommended remediation.
Description
A vulnerability in the Linux kernel's VXLAN VNI filter entry policy allowed a short GROUP/GROUP6 attribute to be accepted, causing an over-read of uninitialized kernel memory. This memory disclosure occurs because the GROUP consumer reads a fixed 4-byte address unconditionally, potentially leaking kernel memory via RTM_GETTUNNEL responses. The issue was fixed by enforcing exact length validation on these attributes.
References
- ubuntu.com/security/CVE-2026-89776 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89776 (opens in a new tab)
- git.kernel.org/linus/984f831dda31b3a18f47454cf64989f65402879e (opens in a new tab)
- git.kernel.org/stable/c/47bfcc871576eaef6c8edab6749acd4b317306ea (opens in a new tab)
- git.kernel.org/stable/c/984f831dda31b3a18f47454cf64989f65402879e (opens in a new tab)
- git.kernel.org/stable/c/a9ec10815199f9879ba080241dc555efb1daf324 (opens in a new tab)
- git.kernel.org/stable/c/ad32e564c62ebf5ba76dd60a22af52c69d54d17b (opens in a new tab)
- git.kernel.org/stable/c/daebc7064a1b4c12c98e52c4bceede7f2fcd573c (opens in a new tab)
- git.kernel.org/stable/c/e12c4663529699f457b2988c1dfedf4d13b3b3be (opens in a new tab)