CVE-2026-27922 Microsoft CVE debrief

Who should care

Defenders and administrators of Windows environments should assess exposure and apply patches to prevent local privilege escalation. They should also monitor system logs for potential exploitation attempts and verify exposure by checking Windows Ancillary Function Driver for WinSock versions and applying patches.

Why it matters

CVE-2026-27922 is a high-severity elevation of privilege vulnerability in Windows Ancillary Function Driver for WinSock. Defenders should verify exposure, apply patches, and monitor system logs to prevent local privilege escalation.

• Verify exposure and apply patches to prevent local privilege escalation
• Assess local privilege escalation risks in Windows environments
• Monitor system logs for potential exploitation attempts

Technical summary

The Windows Ancillary Function Driver for WinSock has a use-after-free vulnerability, allowing an authorized attacker to elevate privileges locally. This vulnerability has a CVSS score of 7 and a severity of HIGH. The CVE record was published on 2026-04-14T16:58:11.466Z and has not been modified since then. Defenders should verify exposure and apply patches to prevent local privilege escalation.

Defensive priority

Defenders should prioritize verifying exposure and applying patches for Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability.

Recommended defensive actions

• Verify exposure by checking Windows Ancillary Function Driver for WinSock versions and applying patches
• Assess local privilege escalation risks in Windows environments
• Monitor system logs for potential exploitation attempts

Evidence notes

The CVE Program record and NVD vulnerability detail provide information on the vulnerability. Microsoft's official advisory is referenced. The vulnerability has a CVSS score of 7 and a severity of HIGH. The CVE record was published on 2026-04-14T16:58:11.466Z and has not been modified since then. Defenders should verify exposure and apply patches to prevent local privilege escalation.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.