CVE-2026-66307

Severity CVSS v4.0:

Pending analysis

Type:

CWE-191 Integer Underflow (Wrap or Wraparound)

Publication date:

08/09/2026

Last modified:

08/09/2026

Description

Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

7.50

Severity 3.x

HIGH

References to Advisories, Solutions, and Tools

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66307