CVE-2026-56649: Windows Network File System Remote Code Execution Vulnerability
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Network File System allows an unauthorized attacker to execute code over a network.
Other sources
Windows Network File System Remote Code Execution Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.14393.9339Patch KB5099535 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.28000.2525Patch KB5101649 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.33158Patch KB5099536 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.8875Patch KB5101650 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.19045.7548Patch KB5099539 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.19044.7548Patch KB5099539 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.20348.5386Patch KB5099540 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.17763.9020Patch KB5099538 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.3.9600.23291Patch KB5099444 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26226Patch KB5099445 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26200.8875Patch KB5101650
Event History
Frequently Asked Questions
What is the severity of CVE-2026-56649?
The severity of CVE-2026-56649 is rated high with a score of 8.1.
How do I fix CVE-2026-56649?
To fix CVE-2026-56649, apply the latest security patch provided by Microsoft.
What type of vulnerability is CVE-2026-56649?
CVE-2026-56649 is a remote code execution vulnerability caused by improper synchronization in the Windows Network File System.
Which Microsoft products are affected by CVE-2026-56649?
CVE-2026-56649 affects Microsoft Windows 10, Windows 11, and various versions of Windows Server including 2012, 2016, 2019, and 2025.
What is the impact of CVE-2026-56649?
The impact of CVE-2026-56649 could allow an unauthorized attacker to execute arbitrary code over a network.