{"id":"CVE-2026-46655","title":"virtio-win provides Windows paravirtualized drivers for QEMU and KVM","summary":"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[*]…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-122","CWE-190"],"vendor":"virtio-win","product":"kvm-guest-drivers-windows","affected":["kvm-guest-drivers-windows >= mm210, < mm320"],"published":"2026-09-18","updated":"2026-09-18","sourceUpdated":"2026-09-18T17:16:57.373","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-46655","references":[{"url":"https://github.com/virtio-win/kvm-guest-drivers-windows/commit/c6bef93d7909584bbda4e5c87603ea175825f342","label":"security-advisories@github.com"},{"url":"https://github.com/virtio-win/kvm-guest-drivers-windows/pull/1568","label":"security-advisories@github.com"},{"url":"https://github.com/virtio-win/kvm-guest-drivers-windows/releases/tag/mm320","label":"security-advisories@github.com"},{"url":"https://github.com/virtio-win/kvm-guest-drivers-windows/security/advisories/GHSA-qrhp-4mhp-hjwh","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-18T17:46:41.519Z","epss":0.0012,"epssPercentile":0.02074,"slug":"CVE-2026-46655","body":"## Overview\n\nvirtio-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}