Live › vulnerability › CVE-2025-21418
Go to dashboardA heap-based buffer overflow in the Windows Ancillary Function Driver for WinSock (afd.sys) lets a local user escalate privileges. An attacker with a local foothold gets SYSTEM privileges, and CISA lists it as exploited in the wild.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 19:11 UTC, 3h before NVD. All times on this page are UTC.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
| Product | Ecosystem | Affected | Fixed in |
|---|---|---|---|
| Microsoft Windows | vendor | – | – |
| microsoft windows 10 1607 | vendor | < 10.0.10240.20915 | 10.0.10240.20915 |
| microsoft windows 10 1809 | vendor | < 10.0.17763.6893 | 10.0.17763.6893 |
| microsoft windows 10 21h2 | vendor | < 10.0.19044.5487 | 10.0.19044.5487 |
| microsoft windows 10 22h2 | vendor | < 10.0.19045.5487 | 10.0.19045.5487 |
| microsoft windows 11 22h2 | vendor | < 10.0.22621.4890 | 10.0.22621.4890 |
| microsoft windows 11 23h2 | vendor | < 10.0.22631.4890 | 10.0.22631.4890 |
| microsoft windows 11 24h2 | vendor | < 10.0.26100.3107 | 10.0.26100.3107 |
| microsoft windows server 2008 | vendor | – | – |
| microsoft windows server 2008 | vendor | = r2 | – |
| microsoft windows server 2012 | vendor | – | – |
| microsoft windows server 2012 | vendor | = r2 | – |
| microsoft windows server 2016 | vendor | < 10.0.14393.7785 | 10.0.14393.7785 |
| microsoft windows server 2019 | vendor | < 10.0.17763.6893 | 10.0.17763.6893 |
| microsoft windows server 2022 | vendor | < 10.0.20348.3148 | 10.0.20348.3148 |
| microsoft windows server 2022 23h2 | vendor | < 10.0.25398.1425 | 10.0.25398.1425 |
| microsoft windows server 2025 | vendor | < 10.0.26100.3107 | 10.0.26100.3107 |
Unknown from the sources.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
Microsoft Windows Ancillary Function Driver for WinSock contains a heap-based buffer overflow vulnerability that allows for privilege escalation, enabling a local attacker to gain SYSTEM privileges.
CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
This page as .md · .json · in your agent: get_signal("CVE-2025-21418")
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