{"id":"CVE-2026-20860","title":"Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.","summary":"Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.","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-843"],"vendor":"microsoft","product":"windows_10_1607","affected":["windows_10_1607 < 10.0.14393.8783","windows_10_1809 < 10.0.17763.8276","windows_10_21h2 < 10.0.19044.6809","windows_10_22h2 < 10.0.19045.6809","windows_11_23h2 < 10.0.22631.6491","windows_11_24h2 < 10.0.26100.7623","windows_11_25h2 < 10.0.26200.7623","windows_server_2008","windows_server_2008 = r2","windows_server_2012","windows_server_2012 = r2","windows_server_2016 < 10.0.14393.8783","windows_server_2019 < 10.0.17763.8276","windows_server_2022 < 10.0.20348.4648","windows_server_2022_23h2 < 10.0.25398.2092","windows_server_2025 < 10.0.26100.32230"],"patched":["windows_10_1607 10.0.14393.8783","windows_10_1809 10.0.17763.8276","windows_10_21h2 10.0.19044.6809","windows_10_22h2 10.0.19045.6809","windows_11_23h2 10.0.22631.6491","windows_11_24h2 10.0.26100.7623","windows_11_25h2 10.0.26200.7623","windows_server_2016 10.0.14393.8783","windows_server_2019 10.0.17763.8276","windows_server_2022 10.0.20348.4648","windows_server_2022_23h2 10.0.25398.2092","windows_server_2025 10.0.26100.32230"],"published":"2026-01-13","updated":"2026-07-30","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-20860","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20860","label":"secure@microsoft.com"}],"tags":["nvd"],"epss":0.084,"epssPercentile":0.94805,"ingestedAt":"2026-07-31T06:58:52.549Z","slug":"CVE-2026-20860","body":"## Overview\n\nAccess of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.\n\n## Affected\n\n- `windows_10_1607 < 10.0.14393.8783`\n- `windows_10_1809 < 10.0.17763.8276`\n- `windows_10_21h2 < 10.0.19044.6809`\n- `windows_10_22h2 < 10.0.19045.6809`\n- `windows_11_23h2 < 10.0.22631.6491`\n- `windows_11_24h2 < 10.0.26100.7623`\n- `windows_11_25h2 < 10.0.26200.7623`\n- `windows_server_2008`\n- `windows_server_2008 = r2`\n- `windows_server_2012`\n- `windows_server_2012 = r2`\n- `windows_server_2016 < 10.0.14393.8783`\n- `windows_server_2019 < 10.0.17763.8276`\n- `windows_server_2022 < 10.0.20348.4648`\n- `windows_server_2022_23h2 < 10.0.25398.2092`\n- `windows_server_2025 < 10.0.26100.32230`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `windows_10_1607 10.0.14393.8783`\n- `windows_10_1809 10.0.17763.8276`\n- `windows_10_21h2 10.0.19044.6809`\n- `windows_10_22h2 10.0.19045.6809`\n- `windows_11_23h2 10.0.22631.6491`\n- `windows_11_24h2 10.0.26100.7623`\n- `windows_11_25h2 10.0.26200.7623`\n- `windows_server_2016 10.0.14393.8783`\n- `windows_server_2019 10.0.17763.8276`\n- `windows_server_2022 10.0.20348.4648`\n- `windows_server_2022_23h2 10.0.25398.2092`\n- `windows_server_2025 10.0.26100.32230`","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":42.9,"likelihood":1.7,"exploitation":0,"ransomware":0},"changes":[]}