Race Condition in Windows SMB Server Enables Privilege Escalation

Publication date: 2026-01-13

Last updated on: 2026-01-13

Assigner: Microsoft Corporation

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-01-13

Last Modified

2026-01-13

Generated

2026-07-06

AI Q&A

2026-01-14

EPSS Evaluated

2026-07-05

NVD

CVE-2026-20848

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_smb_server	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-362	The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Attack-Flow Graph

Executive Summary

This vulnerability is a race condition in the Windows SMB Server where concurrent execution using a shared resource occurs without proper synchronization. This flaw allows an authorized attacker to elevate their privileges over a network.

Impact Analysis

An attacker who is authorized on the network could exploit this vulnerability to gain higher privileges than they should have, potentially allowing them to perform unauthorized actions, access sensitive data, or disrupt system operations.

Hi! I’m here to help you understand CVE-2026-20848. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70