Server-Side Request Forgery (SSRF) in Skype for Business Server and Skype for Business Server Subscription Edition - CVE-2026-66304
Published: September 9, 2026
Vulnerability identifier: #VU148359
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-66304
CWE-ID: CWE-918
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The disclosed vulnerability allows a remote attacker to perform SSRF attacks.
The vulnerability exists due to insufficient validation of user-supplied input in Skype for Business. A remote attacker can send a specially crafted HTTP request and trick the application to initiate requests to arbitrary systems.
Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.
Affected software
Skype for Business Server
Skype for Business Server Subscription Edition
Skype for Business Server Subscription Edition
How to mitigate CVE-2026-66304
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
Skype for Business Server Subscription Edition - update to 7.0.2046.879