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Description

Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

PUBLISHED Reserved 2025-12-03 | Published 2026-01-13 | Updated 2026-02-22 | Assigner microsoft




HIGH: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Problem types

CWE-590: Free of Memory not on the Heap

Product status

10.0.17763.0 (custom) before 10.0.17763.8276
affected

10.0.19044.0 (custom) before 10.0.19044.6809
affected

10.0.19045.0 (custom) before 10.0.19045.6809
affected

10.0.17763.0 (custom) before 10.0.17763.8276
affected

10.0.17763.0 (custom) before 10.0.17763.8276
affected

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20810 (Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability) vendor-advisory patch

cve.org (CVE-2026-20810)

nvd.nist.gov (CVE-2026-20810)

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