Home/CVE/Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate pri
CVE

CVE-2026-21236

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

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

HIGH · CVSS 7.8 EPSS 0.00039
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-122Heap-based Buffer Overflow
CWE-787Out-of-bounds Write
▤

Affected Products & Versions

13
microsoft windows 10 1607< 10.0.14393.8868
microsoft windows 10 1809< 10.0.17763.8389
microsoft windows 10 21h2< 10.0.19044.6937
microsoft windows 10 22h2< 10.0.19045.6937
microsoft windows 11 23h2< 10.0.22631.6649
microsoft windows 11 24h2< 10.0.26100.7781
microsoft windows 11 25h2< 10.0.26200.7781
microsoft windows server 2012all versions
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Scoring & Timeline

7.8
HIGH · CVSS v3.1 · secure@microsoft.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD10 Feb 2026 · 06:16 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
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Vendor Advisories

1
msrcCVE-2026-21236Elevation of Privilege
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