Vulnerability · Published Jan 13, 2026 · Assigned by microsoft
CVE-2026-20810Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
High 7.8
In plain English
A high-severity security flaw in Windows 10 Version 1809 from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).
Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.5%top 57.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 10 Version 1809 | 10.0.17763.0 – before 10.0.17763.8276 |
| Microsoft | Windows 10 Version 21H2 | 10.0.19044.0 – before 10.0.19044.6809 |
| Microsoft | Windows 10 Version 22H2 | 10.0.19045.0 – before 10.0.19045.6809 |
| Microsoft | Windows Server 2019 | 10.0.17763.0 – before 10.0.17763.8276 |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 – before 10.0.17763.8276 |
Weakness: CWE-590 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
References
- Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability vendor-advisory, patch