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CVE-2026-46655 (GCVE-0-2026-46655)

Vulnerability from cvelistv5 – Published: 2026-09-18 16:46 – Updated: 2026-09-18 16:46
VLAI
Title
virtio-win: Integer overflow causing a heap overflow in Viosock driver
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[*].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.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-122 - Heap-based Buffer Overflow
  • CWE-190 - Integer Overflow or Wraparound
Assigner
References
Impacted products
Vendor Product Version CPE status
virtio-win kvm-guest-drivers-windows Affected: >= mm210, < mm320
guessed Create a notification for this product.
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "kvm-guest-drivers-windows",
          "vendor": "virtio-win",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= mm210, \u003c mm320"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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-\u003eFds 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-122",
              "description": "CWE-122: Heap-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-190",
              "description": "CWE-190: Integer Overflow or Wraparound",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-18T16:46:50.352Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/virtio-win/kvm-guest-drivers-windows/security/advisories/GHSA-qrhp-4mhp-hjwh",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/virtio-win/kvm-guest-drivers-windows/security/advisories/GHSA-qrhp-4mhp-hjwh"
        },
        {
          "name": "https://github.com/virtio-win/kvm-guest-drivers-windows/pull/1568",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/virtio-win/kvm-guest-drivers-windows/pull/1568"
        },
        {
          "name": "https://github.com/virtio-win/kvm-guest-drivers-windows/commit/c6bef93d7909584bbda4e5c87603ea175825f342",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/virtio-win/kvm-guest-drivers-windows/commit/c6bef93d7909584bbda4e5c87603ea175825f342"
        },
        {
          "name": "https://github.com/virtio-win/kvm-guest-drivers-windows/releases/tag/mm320",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/virtio-win/kvm-guest-drivers-windows/releases/tag/mm320"
        }
      ],
      "source": {
        "advisory": "GHSA-qrhp-4mhp-hjwh",
        "discovery": "UNKNOWN"
      },
      "title": "virtio-win: Integer overflow causing a heap overflow in Viosock driver"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-46655",
    "datePublished": "2026-09-18T16:46:34.832Z",
    "dateReserved": "2026-05-15T20:11:54.585Z",
    "dateUpdated": "2026-09-18T16:46:50.352Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-46655",
      "date": "2026-09-19",
      "epss": "0.0012",
      "percentile": "0.02078"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "kvm-guest-drivers-windows",
                "vendor": "virtio-win",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003e= mm210, \u003c mm320"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "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-\u003eFds 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."
          }
        ],
        "id": "CVE-2026-46655",
        "lastModified": "2026-09-18T17:16:57.373",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 5.9,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-09-18T17:16:57.373",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/virtio-win/kvm-guest-drivers-windows/commit/c6bef93d7909584bbda4e5c87603ea175825f342"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/virtio-win/kvm-guest-drivers-windows/pull/1568"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/virtio-win/kvm-guest-drivers-windows/releases/tag/mm320"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/virtio-win/kvm-guest-drivers-windows/security/advisories/GHSA-qrhp-4mhp-hjwh"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Received",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-122"
              },
              {
                "lang": "en",
                "value": "CWE-190"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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