CVE-2026-68820 - Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability

Technical Severity

CVSS v3.1 Metrics

HIGH

7 / 10

Minimal Risk Critical

Vector Specification

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation Likelihood

EPSS Prediction

6.18 %

Predictive Probability

Percentile Rank

93.0 th

Documented as more likely to be exploited than 93.0% of known CVEs.

Detection Date

Aug 11, 2026

Remediation Due

Aug 25, 2026

CISA Catalog Active

Threat Analysis

Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to elevate privileges locally.

Remediation Directive

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

External Intelligence

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-68820

CISA

CISA Advisory

https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk

CISA

CISA Advisory

https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk

NVD

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2026-68820