Local privilege escalation via AFD heap overflow
Published Oct 14, 2025 · Updated Feb 26, 2026
Heap-based buffer overflow in Microsoft Windows AFD.sys allows local users with low privileges to elevate privileges through local driver access. Microsoft identifies an integer underflow and resulting heap overflow in the Ancillary Function Driver for WinSock but does not disclose the faulty routine or input operation. Exploitation requires existing local low-privilege access and can grant elevated control over the affected system.
Summary
What happened
Heap-based buffer overflow in Microsoft Windows AFD.sys allows local users with low privileges to elevate privileges through local driver access. Microsoft identifies an integer underflow and resulting heap overflow in the Ancillary Function Driver for WinSock but does not disclose the faulty routine or input operation. Exploitation requires existing local low-privilege access and can grant elevated control over the affected system.
The record
- CVE
- CVE-2025-59242
- Published
- Oct 14, 2025
- Updated
- Feb 26, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-122, CWE-191, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 14, 2025CVE publishedPublication date reported by the CVE source.
- Feb 26, 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=10.0.10240.0 <10.0.10240.21161
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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