CVE-2026-20939: Windows File Explorer Information Disclosure Vulnerability
This Microsoft advisory covers CVE-2026-20939 in Windows Server 2016 (Server Core installation), Windows Server 2019 (Server Core installation) and Windows Server 2022, 23H2 Edition (Server Core installation).
- CVE-2026-20939
Key facts
- Vendor rating
- Medium, CVSS 5.5
- CISA KEV
- Not listed (catalogue checked )
- Affected
- Windows 10 Version 1607 10.0.14393.0 before 10.0.14393.8783; Windows 10 Version 1809 10.0.17763.0 before 10.0.17763.8276; Windows 10 Version 21H2 10.0.19044.0 before 10.0.19044.6809 and 9 more below
- Fixed in
- 10.0.14393.8783, 10.0.17763.8276, 10.0.19044.6809 and 7 more below
- Source published
- Source revised
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
Exposure of sensitive information to an unauthorized actor in Windows File Explorer allows an authorized attacker to disclose information locally.
Affected products named by the advisory: Windows Server 2016; Windows Server 2016 (Server Core installation); Windows Server 2019; Windows Server 2019 (Server Core installation); and 4 more.
Affected products named by the advisory: Windows Server 2022, 23H2 Edition (Server Core installation); Windows Server 2025 (Server Core installation).
Text from the source record.
- Windows 10 Version 1607 10.0.14393.0 before 10.0.14393.8783
- Windows 10 Version 1809 10.0.17763.0 before 10.0.17763.8276
- Windows 10 Version 21H2 10.0.19044.0 before 10.0.19044.6809
- Windows 10 Version 22H2 10.0.19045.0 before 10.0.19045.6809
- Windows 11 version 23H2 10.0.22631.0 before 10.0.22631.6491
- Windows 11 Version 23H2 10.0.22631.0 before 10.0.22631.6491
- Windows 11 Version 24H2 10.0.26100.0 before 10.0.26100.7623
- Windows 11 Version 25H2 10.0.26200.0 before 10.0.26200.7623
- Windows Server 2016 10.0.14393.0 before 10.0.14393.8783
- Windows Server 2016 (Server Core installation) 10.0.14393.0 before 10.0.14393.8783
- Windows Server 2019 10.0.17763.0 before 10.0.17763.8276
- Windows Server 2019 (Server Core installation) 10.0.17763.0 before 10.0.17763.8276
Official advisory · high-confidence parse· fetched ·verify at source
How to fix CVE-2026-20939
Upgrade to a fixed release named by Microsoft:
- 10.0.14393.8783
- 10.0.17763.8276
- 10.0.19044.6809
- 10.0.19045.6809
- 10.0.22631.6491
- 10.0.26100.7623
- 10.0.26200.7623
- 10.0.20348.4648
- 10.0.25398.2092
- 10.0.26100.32230
End-of-life dates for Windows Server
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