Local privilege escalation via AFD race condition
Published Apr 14, 2026 · Updated Apr 14, 2026
Race condition in Microsoft Windows AFD for WinSock allows local users with low privileges to elevate privileges on affected Windows releases. Microsoft identifies improper synchronization during concurrent use of a shared resource in the driver but has not published the specific code path, shared object, or incorrect operation. Exploitation requires local access, low privileges, and a difficult-to-win race; success elevates the attacker’s privileges on the host.
Summary
What happened
Race condition in Microsoft Windows AFD for WinSock allows local users with low privileges to elevate privileges on affected Windows releases. Microsoft identifies improper synchronization during concurrent use of a shared resource in the driver but has not published the specific code path, shared object, or incorrect operation. Exploitation requires local access, low privileges, and a difficult-to-win race; success elevates the attacker’s privileges on the host.
The record
- CVE
- CVE-2026-26173
- Published
- Apr 14, 2026
- Updated
- Apr 14, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-362, CWE-416, CWE-476, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 14, 2026CVE publishedPublication date reported by the CVE source.
- Apr 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.8644
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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