CVE-2026-46655: virtio-win kvm-guest-drivers-windows · Heap-based Buffer Overflow
Affects virtio-win kvm-guest-drivers-windowsSource CVE Database V5
Not known to be exploited · CVSS 7.8 High : upgrade to mm320 soon.
Data as of 2 Nov 2026, 10:58 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in mm320
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Sep 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 2 Nov 2026.
What to do
Upgrade kvm-guest-drivers-windows and virtio-win/kvm-guest-drivers-windows to mm320.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| virtio-winkvm-guest-drivers-windows | Affected
| Fixed in
|
GitHubvirtio-win/kvm-guest-drivers-windowspkg:github/virtio-win/kvm-guest-drivers-windowsOther 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
This vulnerability is fixed in virtio-win version mm320. Users should upgrade to version mm320 or later to remediate this issue. No other mitigation or temporary workaround is indicated in the available data.
Description
virtio-win provides Windows paravirtualized drivers for QEMU and KVM. From mm210 until mm320, the Viosock driver permits a low-privilege local process to submit an IOCTL_SELECT request with attacker-controlled VIRTIO_VSOCK_SELECT.Fdss[*].fd_count values that overflow the 32-bit sum used by VIOSockSelect for bounds checking. The wrapped sum can pass the FD_SETSIZE check even though an individual descriptor count is much larger than the expected limit. VIOSockSelectCopyFds then iterates using the unchecked count and writes beyond the allocated pPkt->Fds array in the NonPagedPool kernel heap. Successful exploitation can corrupt kernel memory and enable privilege escalation in a Windows guest running the driver. This issue is fixed in mm320.
References
- github.com/virtio-win/kvm-guest-drivers-windows/security/advisories/GHSA-qrhp-4mhp-hjwh (opens in a new tab)
- github.com/virtio-win/kvm-guest-drivers-windows/pull/1568 (opens in a new tab)
- github.com/virtio-win/kvm-guest-drivers-windows/commit/c6bef93d7909584bbda4e5c87603ea175825f342 (opens in a new tab)
- github.com/virtio-win/kvm-guest-drivers-windows/releases/tag/mm320 (opens in a new tab)