What is CVE-2026-83504?

CVE-2026-83504 is a medium-severity vulnerability in Microsoft Windows 11 Version 23h2, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 4.7/10. Published 2026-10-13.

How severe is CVE-2026-83504?

Medium severity. CVSS v3 base score is 4.7 out of 10.

Vulnerability in Microsoft Windows 11 Version 23h2

CVE-2026-83504

Time-of-check time-of-use (toctou) race condition in Windows SmartScreen allows an authorized attacker to disclose information locally.

Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)

Published 2026-10-13 · last modified 2026-10-13.

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83504 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-83504?: CVE-2026-83504 is a medium-severity vulnerability in Microsoft Windows 11 Version 23h2, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 4.7/10. Published 2026-10-13.
How severe is CVE-2026-83504?: Medium severity. CVSS v3 base score is 4.7 out of 10.