CVE-2026-20919CWE-362

CVE-2026-20919

High · published January 13, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
56.1
In the wild
Unconfirmed
What it is

⚡ A race condition in Windows SMB Server lets an authorized attacker boost their privileges by exploiting shared resources — it's like a sneaky teammate who shows up to the finish line first! Imagine a relay race where one runner secretly starts a second lap while the baton is still being passed! If the baton isn't handled properly, one runner could take off with an unfair advantage, just like how this vulnerability can be exploited to elevate user privileges behind the scenes. An attacker could gain unauthorized access at higher privilege levels, allowing them to manipulate files, access sensitive data, or even take control of the system. This could lead to a severe breach of security and data integrity, affecting the entire network.

Put simply

Imagine a relay race where one runner secretly starts a second lap while the baton is still being passed! If the baton isn't handled properly, one runner could take off with an unfair advantage, just like how this vulnerability can be exploited to elevate user privileges behind the scenes. This vulnerability arises from improper synchronization during concurrent execution, allowing an authorized user to exploit shared resources. This race condition can be triggered remotely over the network, leading to privilege escalation.

What to do

An attacker could gain unauthorized access at higher privilege levels, allowing them to manipulate files, access sensitive data, or even take control of the system. This could lead to a severe breach of security and data integrity, affecting the entire network. To mitigate this risk, ensure you apply the latest security patch provided by Microsoft as soon as possible. Additionally, review your user access controls to limit unnecessary privileges and enhance monitoring for unusual activities. Keep systems updated regularly! You've got this! With a couple of patches and some diligence, you can keep your systems safe and sound. 🛡️

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00799 · 56.1th percentile
Weakness
CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Published
2026-01-13T23:16Z
Affected products (16)
ProductVersionsFixed in
microsoft/windows_10_1607< 10.0.14393.878310.0.14393.8783
microsoft/windows_10_1607< 10.0.14393.878310.0.14393.8783
microsoft/windows_10_1809< 10.0.17763.827610.0.17763.8276
microsoft/windows_10_1809< 10.0.17763.827610.0.17763.8276
microsoft/windows_10_21h2< 10.0.19044.680910.0.19044.6809
microsoft/windows_10_22h2< 10.0.19045.680910.0.19045.6809
microsoft/windows_11_23h2< 10.0.22631.649110.0.22631.6491
microsoft/windows_11_24h2< 10.0.26100.762310.0.26100.7623
microsoft/windows_11_25h2< 10.0.26200.762310.0.26200.7623
microsoft/windows_server_2012all versions—
microsoft/windows_server_2012all versions—
microsoft/windows_server_2016< 10.0.14393.878310.0.14393.8783
microsoft/windows_server_2019< 10.0.17763.827610.0.17763.8276
microsoft/windows_server_2022< 10.0.20348.464810.0.20348.4648
microsoft/windows_server_2022_23h2< 10.0.25398.209210.0.25398.2092
microsoft/windows_server_2025< 10.0.26100.3223010.0.26100.32230
References (1)
EPSS history
Timeline
  • 13 JAN 17:56Z
    Windows SMB Server Elevation of Privilege Vulnerability
    cvelistv5