CVE-2026-45638

CVE-2026-45638

Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

secure@microsoft.com

Frequently asked questions

What is CVE-2026-45638?: CVE-2026-45638 is a high-severity vulnerability, classified under Heap-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-06-09.
How severe is CVE-2026-45638?: High severity. CVSS v3 base score is 7.8 out of 10.