What is the CVSS score of CVE-2026-20931?

CVE-2026-20931 has a CVSS 3.1 base score of 8.0 (High). CVSS vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.8%.

Which versions of Microsoft are affected by CVE-2026-20931?

Organizations using External control of file name or path in Windows Telephony Service face notable risk from CVE-2026-20931 rated CVSS 8.0.. A patch is available.

How to fix or mitigate CVE-2026-20931?

Within 7 days: Identify all affected systems and apply vendor patches promptly. Monitor vendor channels for patch availability.

Microsoft CVE-2026-20931

HIGH

External Control of File Name or Path (CWE-73)

2026-01-13 secure@microsoft.com

Microsoft Information Disclosure

8.0

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.0 HIGH

AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

CVE Published

Jan 13, 2026 - 18:16 nvd

HIGH 8.0

DescriptionCVE.org

External control of file name or path in Windows Telephony Service allows an authorized attacker to elevate privileges over an adjacent network.

AnalysisAI

Windows Telephony Service on multiple Windows versions (10, 11, Server 2008/2022) contains an improper file path control vulnerability that enables authenticated attackers on the same network to escalate privileges to system level. An attacker with local user credentials can manipulate file name or path parameters to achieve elevated privileges without user interaction. No patch is currently available, though the vulnerability has high exploitability potential (EPSS 0.8%).

Technical ContextAI

Affects the Windows Telephony component of Windows 10 1607. External control of file name or path in Windows Telephony Service allows an authorized attacker to elevate privileges over an adjacent network.