Main Vulnerability Database Vulnerabilities #VU148360

Use of Client-Side Authentication in Skype for Business Server and Skype for Business Server Subscription Edition - CVE-2026-66305

Published: September 9, 2026

Vulnerability identifier: #VU148360

CSH Severity: Medium

CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-66305

CWE-ID: CWE-603

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to use of client-side authentication in Skype for Business. A remote user can perform spoofing attack.

Skype for Business Server
Skype for Business Server Subscription Edition

Install updates from vendor's website.

Skype for Business Server - addressed in versions 6.0.9319.885, 7.0.2046.569
Skype for Business Server Subscription Edition - update to 7.0.2046.879