CVE-2026-99216: Linux kernel · Drivers: hv: Don't reset VMBus connection state on error/exit paths
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 29 Oct 2026, 22:37 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther 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 corrects the handling of the VMBus connection state by not forcibly setting it to DISCONNECTED during error or exit paths. Users should apply the updated Linux kernel versions that include this fix. No additional mitigation steps are specified or required beyond applying the official patch.
Description
A vulnerability in the Linux kernel's Hyper-V driver (hv) involves improper resetting of the VMBus connection state on error or exit paths. The issue causes the connection state to be set to DISCONNECTED prematurely, preventing proper unloading of the VMBus connection. This can result in the Hyper-V host continuing to send messages or post interrupts despite the connection being considered disconnected. The flaw was introduced by a commit that changed how connection state was checked before unloading. The fix prevents forcibly setting the connection state to DISCONNECTED during exit or failure to establish the connection.
References
- ubuntu.com/security/CVE-2026-99216 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99216 (opens in a new tab)
- git.kernel.org/stable/c/ec31dc39e835ccde0930daccece8c492d28282fc (opens in a new tab)
- git.kernel.org/stable/c/f47ce27af80b87cc684d5c12b65506af498ac7e5 (opens in a new tab)
- git.kernel.org/stable/c/3195546a377c2d8d176d837e8baad5ce15d11195 (opens in a new tab)