CVE-2026-20848
Published: 13 January 2026
Summary
CVE-2026-20848 is a high-severity Race Condition (CWE-362) vulnerability in Microsoft Windows 10 1607. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and AC-6 (Least Privilege).
Deeper analysis
CVE-2026-20848 is a race condition vulnerability (CWE-362) stemming from concurrent execution using a shared resource with improper synchronization in the Windows SMB Server. Published on 2026-01-13, it enables an authorized attacker to elevate privileges over a network and carries a CVSS v3.1 base score of 7.5 (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H).
The vulnerability can be exploited by an attacker with low privileges (PR:L) over the network (AV:N), though it demands high attack complexity (AC:H) and requires no user interaction (UI:N). Successful exploitation results in high impacts across confidentiality, integrity, and availability (C:H/I:H/A:H) within an unchanged scope (S:U), allowing the attacker to escalate privileges on the affected system.
Mitigation details are available in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20848.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-2166
Vulnerability details
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Race condition in Windows SMB Server directly enables remote privilege escalation by an authenticated low-privileged attacker (T1068).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Timely flaw remediation through vendor patches directly eliminates the race condition vulnerability in the Windows SMB Server.
Enforcement of least privilege limits the capabilities of low-privilege (PR:L) accounts that could attempt to exploit the race condition for privilege escalation.
Boundary protection restricts network access (AV:N) to the SMB server, preventing unauthorized low-privilege remote attackers from reaching and exploiting the vulnerability.