CVE-2026-21236

CWE-122 — Heap-based Buffer OverflowCWE-787 — Out-of-bounds Write5 documents5 sources
Severity
7.8HIGH
EPSS
0.0%
top 90.37%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
28
Microsoft Windows 10 Version 1607Microsoft Windows 10 Version 1809Microsoft Windows 10 Version 21h2+25 more
Timeline
PublishedFeb 10

Description

Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitability: 1.8 | Impact: 5.9

Affected Packages28 packages

▶NVDmicrosoft/windows< 10.0.14393.8868+5
▶NVDmicrosoft/windows_10_1607< 10.0.14393.8868
▶NVDmicrosoft/windows_10_1809< 10.0.17763.8389
▶NVDmicrosoft/windows_10_21h2< 10.0.19044.6937
▶NVDmicrosoft/windows_10_22h2< 10.0.19045.6937

🔴Vulnerability Details

2
GHSA
GHSA-35fp-m999-3h79: Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally↗2026-02-10
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CVEList
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability↗2026-02-10
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📋Vendor Advisories

1
Microsoft
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability↗2026-02-10
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🕵️Threat Intelligence

1
Wiz
CVE-2026-21236 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2026-21236 (HIGH CVSS 7.8) | Heap-based buffer overflow in Windo | cvebase.io