What is CVE-2026-42836?

CVE-2026-42836 is a high-severity vulnerability in Microsoft Windows_10_1607, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2026-06-09.

How severe is CVE-2026-42836?

High severity. CVSS v3 base score is 7.0 out of 10.

Use After Free in Microsoft Windows_10_1607

CVE-2026-42836

Concurrent execution using shared resource with improper synchronization ('race condition') in Function Discovery Service (fdwsd.dll) allows an authorized attacker to elevate privileges locally.

Vulnerability class: Race Condition

CVSS v3 metric

CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Microsoft Windows_10_1607
Microsoft Windows_10_1809
Microsoft Windows_10_21h2
Microsoft Windows_10_22h2
Microsoft Windows_11_23h2
Microsoft Windows_11_24h2
Microsoft Windows_11_25h2
Microsoft Windows_11_26h1
Microsoft Windows_server_2012 — versions r2
Microsoft Windows_server_2016

Weakness classification (CWE)

CWE-362 — Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition)
CWE-416 — Use After Free

References

secure@microsoft.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-42836?: CVE-2026-42836 is a high-severity vulnerability in Microsoft Windows_10_1607, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2026-06-09.
How severe is CVE-2026-42836?: High severity. CVSS v3 base score is 7.0 out of 10.