Skip to main content
Live Webinar with SANS (June 25)— Agentic CTI Automation for Fun & ProfitRegister Free
Mallory
High

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

IdentifiersCVE-2026-26173CWE-362· Concurrent Execution using Shared…

CVE-2026-26173 is a local elevation-of-privilege vulnerability in the Windows Ancillary Function Driver for WinSock (AFD.sys). The issue is described as concurrent execution using a shared resource with improper synchronization, i.e., a race condition. An authorized local attacker could exploit this synchronization flaw to elevate privileges on the affected system. The provided content does not include the specific vulnerable function, code path, or affected Windows versions.

Share:
For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows a local authorized attacker to elevate privileges on the target Windows system. In practical terms, this can enable execution with higher privileges than initially granted, potentially facilitating full compromise of the local host depending on the starting context and target configuration. The provided content does not specify the exact resulting integrity level or whether SYSTEM privileges are attainable.

Mitigation

If you can’t patch tonight, do this now.

No specific mitigation is provided in the supplied content. Because this is a local authorized-user race-condition elevation-of-privilege issue in a core Windows component, practical mitigation is limited to reducing local attacker access, enforcing least privilege, restricting interactive/logon access to trusted users, and applying the vendor patch promptly.

Remediation

Patch, then assume compromise.

Apply Microsoft's security update for CVE-2026-26173 as provided in the April 2026 Patch Tuesday release. The supplied content does not include product-specific KB numbers, affected version details, or additional vendor remediation guidance.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Microsoft CorporationWindowsoperating_system
Microsoft CorporationWindows 10 1607operating_system
Microsoft CorporationWindows 10 1809operating_system
Microsoft CorporationWindows 10 21h2operating_system
Microsoft CorporationWindows 10 22h2operating_system
Microsoft CorporationWindows 11 23h2operating_system
Microsoft CorporationWindows 11 24h2operating_system
Microsoft CorporationWindows 11 25h2operating_system
Microsoft CorporationWindows 11 26h1operating_system
Microsoft CorporationWindows Server 2012operating_system
Microsoft CorporationWindows Server 2012 R2operating_system
Microsoft CorporationWindows Server 2016operating_system
Microsoft CorporationWindows Server 2019operating_system
Microsoft CorporationWindows Server 2022operating_system
Microsoft CorporationWindows Server 2022 23h2operating_system
Microsoft CorporationWindows Server 2025operating_system
Microsoft CorporationWindows Server 23h2operating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.