Local privilege escalation via heap buffer overflow
Published Jun 9, 2026 · Updated Jun 9, 2026
Heap-based buffer overflow in Windows AFD for WinSock allows local users to elevate privileges on affected Windows releases. Microsoft has not disclosed the AFD code path, attacker-controlled input, or memory-copy operation that overruns the heap buffer. Successful exploitation requires local low-privilege access and yields higher privileges without user interaction; remote exposure is not reported.
Summary
What happened
Heap-based buffer overflow in Windows AFD for WinSock allows local users to elevate privileges on affected Windows releases. Microsoft has not disclosed the AFD code path, attacker-controlled input, or memory-copy operation that overruns the heap buffer. Successful exploitation requires local low-privilege access and yields higher privileges without user interaction; remote exposure is not reported.
The record
- CVE
- CVE-2026-45638
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-122, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 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 <10.0.17763.8880
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.
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Technologies
Your stack
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Your stack
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