CVE-2026-56648 Details
Description
Time-of-check time-of-use (toctou) race condition in Windows Network File System allows an authorized attacker to elevate privileges over a network.
A time-of-check time-of-use (TOCTOU) race condition vulnerability has been identified in the Windows Network File System (NFS) server. This vulnerability allows an authorized attacker to elevate privileges over the network. It affects multiple Windows versions, including Windows Server 2012 R2, Windows Server 2012, Windows Server 2016, Windows Server 2022, Windows Server 2019, Windows 10 (various versions), and Windows 11 (various versions).
Users can apply the security update provided by Microsoft. This update is available through the Microsoft Update Catalog. Specific update details can be found in the Microsoft Knowledge Base articles KB5099444, KB5099445, KB5099535, KB5099540, KB5099538, KB5099539, and KB5101649.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 14, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56648 | [email protected] | PatchVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-367 | Time-of-check Time-of-use (TOCTOU) Race Condition | [email protected] |
| CWE-416 | Use After Free | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| microsoft windows 10 1607 | < 10.0.14393.9339 |
CPE
Remediation
| |
| microsoft windows 10 1809 | < 10.0.17763.9020 |
CPE
Remediation
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| microsoft windows 10 21h2 | < 10.0.19044.7548 |
CPE
Remediation
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| microsoft windows 10 22h2 | < 10.0.19045.7548 |
CPE
Remediation
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| microsoft windows 11 24h2 | < 10.0.26100.8875 |
CPE
Remediation
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| microsoft windows 11 25h2 | < 10.0.26200.8875 |
CPE
Remediation
| |
| microsoft windows 11 26h1 | < 10.0.28000.2269 |
CPE
Remediation
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| microsoft windows server 2012 | r2 |
CPE
Remediation
| |
| microsoft windows server 2016 | < 10.0.14393.9339 |
CPE
Remediation
| |
| microsoft windows server 2019 | < 10.0.17763.9020 |
CPE
Remediation
| |
| microsoft windows server 2022 | < 10.0.20348.5386 |
CPE
Remediation
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| microsoft windows server 2025 | < 10.0.26100.33158 |
CPE
Remediation
| |
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 22, 2026 | CVE Modified | [email protected] |
| Jul 17, 2026 | Initial Analysis | [email protected] |
| Jul 15, 2026 | CVE Modified | CISA-ADP |
| Jul 14, 2026 | CVE Modified | CISA-ADP |
| Jul 14, 2026 | New CVE Received | [email protected] |