What is the CVSS score of CVE-2026-25188?

CVE-2026-25188 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Windows are affected by CVE-2026-25188?

A critical heap-based buffer overflow in Windows Telephony Service (CVE-2026-25188) allows attackers on adjacent networks to gain elevated system privileges without a vendor patch currently…. A patch is available.

How to fix or mitigate CVE-2026-25188?

Within 24 hours: Identify and inventory all Windows systems with Telephony Service enabled; disable the service on non-essential systems and restrict network access to Telephony Service ports. Within 7 days: Implement network segmentation to isolate systems running Telephony Service; deploy enhanced monitoring for suspicious Telephony Service activity; brief IT and security teams on incident response procedures. Within 30 days: Establish a formal patch management watch for vendor remediation; evaluate alternative telephony solutions; conduct penetration testing on affected systems to verify compensating controls.

Windows CVE-2026-25188

HIGH

Heap-based Buffer Overflow (CWE-122)

2026-03-10 secure@microsoft.com

Windows Buffer Overflow Heap Overflow Microsoft Windows 10 1607 Windows 10 1809 Windows 10 21h2 Windows 10 22h2 Windows 11 23h2 Windows 11 24h2 Windows 11 25h2 Windows 11 26h1 Windows Server 2012 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 2022 23h2 Windows Server 2025

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

CVE Published

Mar 10, 2026 - 18:18 nvd

HIGH 8.8

DescriptionCVE.org

Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to elevate privileges over an adjacent network.

AnalysisAI

Privilege escalation in Windows Telephony Service through heap buffer overflow affects Windows 10 1607, Windows 11 25h2, and Windows Server 2012, allowing adjacent network attackers to gain elevated system access without authentication. The vulnerability has a high CVSS score of 8.8 but currently lacks a patch, creating significant risk for exposed systems. Exploitation requires network proximity but no user interaction.

Technical ContextAI

Classified as CWE-122 (Heap-based Buffer Overflow). Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to elevate privileges over an adjacent network.