CVE-2026-21241 is a use-after-free vulnerability in the Windows Ancillary Function Driver for WinSock, affecting multiple versions of Microsoft Windows 11 and Windows Server 2022/2025. This high-severity flaw (CVSS 7.0) allows an authenticated local attacker to achieve privilege escalation with high impact on confidentiality, integrity, and availability, though the attack complexity is also high. While there is no evidence of active exploitation, public exploit code, or KEV listing, the vulnerability has garnered significant community discussion and media coverage, indicating notable attention from security researchers.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 10.0.22631.6649CPE matchmatch criteria | cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* | ||
< 10.0.22631.6649CPE matchmatch criteria | cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* | ||
< 10.0.26100.7781CPE matchmatch criteria | cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* | ||
< 10.0.26100.7781CPE matchmatch criteria | cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* | ||
< 10.0.26200.7781CPE matchmatch criteria | cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.
The average CVE in this peer group has 0.4 InfoSec Media, 0.1 Vendor Blog, and 0.0 Security Researcher mentions.