CVE-2026-20921

CWE-362 — Race Condition5 documents5 sources
Severity
7.5HIGH
EPSS
0.1%
top 83.73%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
32
Microsoft Windows 10 Version 1607Microsoft Windows 10 Version 1809Microsoft Windows 10 Version 21h2+29 more
Timeline
PublishedJan 13

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HExploitability: 1.6 | Impact: 5.9

Affected Packages31 packages

▶CVEListV5microsoft/windows_server_20126.2.9200.0 — 6.2.9200.25868
▶CVEListV5microsoft/windows_server_201610.0.14393.0 — 10.0.14393.8783
▶CVEListV5microsoft/windows_server_201910.0.17763.0 — 10.0.17763.8276
▶CVEListV5microsoft/windows_server_202210.0.20348.0 — 10.0.20348.4648
▶CVEListV5microsoft/windows_server_202510.0.26100.0 — 10.0.26100.32230

🔴Vulnerability Details

2
CVEList
Windows SMB Server Elevation of Privilege Vulnerability↗2026-01-13
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GHSA
GHSA-rj95-xj64-7m2x: Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to ele↗2026-01-13
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📋Vendor Advisories

1
Microsoft
Windows SMB Server Elevation of Privilege Vulnerability↗2026-01-13
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🕵️Threat Intelligence

1
Wiz
CVE-2026-20921 Impact, Exploitability, and Mitigation Steps | Wiz↗
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