CVE-2026-68820: Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to elevate privileges locally.
CSIRTS triage
- What
- Use-after-free vulnerability in Windows Ancillary Function Driver for WinSock permits authorized attackers to elevate privileges locally.
- Who is affected
- Windows systems with authorized local users capable of exploiting the vulnerable driver.
- Urgency
- Critical severity; actively exploited and enables privilege escalation.
- Action
- Deploy Microsoft security patches containing the fix for CVE-2026-68820 immediately.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-68820
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2026-68820Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 26% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-68820 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownexploitedMicrosoft Monthly Security Update (August 2026)hkcert
- unknownexploitedSecurity Alert: Microsoft Releases August 2026 Security Updatesjpcert
- unknownexploitedMultiple vulnerabilities in Microsoft Windows (August 12, 2026)cert-fr-avis
- unknownexploitedNCSC-2026-0284 [1.00] [M/H] Vulnerabilities patched in Microsoft Windowsncsc-nl
- highexploitedCVE-2026-68820: Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker …nvd
- highexploitedCISA Adds Three Known Exploited Vulnerabilities to Catalogcisa
- highexploitedCVE-2026-68820: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerabilitymsrc
Recent advisories for Microsoft Windows Ancillary
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- criticalexploitedCVE-2025-32709: Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerabilitycisa-kev · 2025-05-13
- criticalexploitedCVE-2025-21418: Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerabili…cisa-kev · 2025-02-11
- criticalexploitedCVE-2024-38193: Microsoft Windows Ancillary Function Driver for WinSock Privilege Escalation Vulnerabilitycisa-kev · 2024-08-13
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