CVE-2026-21241 json
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
published 2026-02-10 8 mo ago modified 2026-08-19 2 mo ago also EUVD-2026-7319
- cvss
- 7.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.6%
- EPSS 2.6% chance of exploitation in 30 days, percentile 85%
- public exploits
- 0
- none known
Summary
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Patch / fix
- Microsoft Windows 11 version 22H3 10.0.22631.6649
- Microsoft Windows 11 Version 23H2 10.0.22631.6649
- Microsoft Windows 11 Version 24H2 10.0.26100.7840
- Microsoft Windows 11 Version 25H2 10.0.26200.7840
- Microsoft Windows 11 version 26H1 10.0.28000.1575
- Microsoft Windows Server 2022 10.0.20348.4773
- Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.2149
- Microsoft Windows Server 2025 10.0.26100.32370
- Microsoft Windows Server 2025 (Server Core installation) 10.0.26100.32370
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 8 mo ago
Exploit prediction
2.56% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C |
| CNA | 3.1 | 7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Microsoft Windows 11 version 22H3
- Microsoft Windows 11 Version 23H2
- Microsoft Windows 11 Version 24H2
- Microsoft Windows 11 Version 25H2
- Microsoft Windows 11 version 26H1
- Microsoft Windows Server 2022
- Microsoft Windows Server 2022, 23H2 Edition (Server Core installation)
- Microsoft Windows Server 2025
- Microsoft Windows Server 2025 (Server Core installation)
Classification
- Weakness
-
- CWE-416 Use After Free
References
-
msrc.microsoft.com
/update-guide/vulnerability/CVE-2026-21241
vendor-advisory, patch
Sources
- CVE List CVE-2026-21241
- NVD CVE-2026-21241
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