CVE-2026-20927
MediumCVSS 5.3Exploitation Probability (EPSS)
Elevated risk56th percentile - higher than 56% of all known CVEs
Summary
A race condition in Windows SMB Server allows an authenticated attacker to cause a denial of service over the network.
Risk Assessment
An attacker can disrupt SMB services, affecting file and printer access across the network and causing downtime.
Recommendation
Apply the Microsoft security update for Windows and restrict SMB access to trusted hosts only.
Other vulnerabilities in Windows SMB Server
See all- CVE-2026-26128High
Improper authentication in Windows SMB Server allows an authorized attacker to elevate privileges locally.
- CVE-2019-0703MediumActively exploited
An information disclosure vulnerability exists in the way that the Windows SMB Server handles certain requests, aka 'Windows SMB Information Disclosure Vulnerability'. This CVE ID is unique from CVE-2019-0704 and CVE-2019-0821.
- CVE-2026-72949High
Null pointer dereference in Windows SMB Server Network Transport Driver (srvnet.sys) allows an unauthorized attacker to deny service over a network.
- CVE-2026-69403Medium
A missing authorization vulnerability in Windows SMB Server allows an authorized attacker to disclose information locally.
- CVE-2026-69374Medium
The vulnerability in Windows SMB Server is an allocation of resources without limits or throttling. It allows an authorized attacker to deny service over a network.
- CVE-2026-62800High
Heap-based buffer overflow in Windows SMB Server allows an authorized attacker to execute code over a network.
- CVE-2026-62790High
Heap-based buffer overflow in Windows SMB Server allows an authorized attacker to execute code over a network.
- CVE-2026-57089High
Use-after-free vulnerability in Windows SMB Server Network Transport Driver (srvnet.sys) allows an unauthorized attacker to execute code over a network.
- CVE-2026-56168Medium
A null pointer dereference in Windows SMB Server allows an authorized attacker to cause a denial of service over the network.
- CVE-2026-50360High
Incorrect implementation of the authentication algorithm in Windows SMB Server allows an authorized attacker to elevate privileges over a network.
Original NVD description (English source)
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to deny service over a network.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS