CVE-2026-66304 Skype for Business Information Disclosure Vulnerability
An unauthorized attacker can exploit a server-side request forgery flaw in Skype for Business to disclose sensitive information over the network.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-66304?
CVE-2026-66304 is a high-severity server-side request forgery vulnerability in Microsoft Skype for Business Server 2015 CU13, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Server-side request forgery (ssrf) in Skype for Business allows an unauthorized attacker to disclose information over a network.
Weakness: CWE-918
Which versions are affected by CVE-2026-66304?
It affects 2 products.
Products include Microsoft Skype for Business Server, Microsoft Skype for Business Server Subscription Edition.
How do I fix CVE-2026-66304?
No fix has been published for CVE-2026-66304 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-66304 being exploited?
There is no known exploitation of CVE-2026-66304 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Skype for Business Server 2015 CU13
- CVE-2023-41763 Microsoft Skype for Business Privilege Escalation
- CVE-2026-66302 Skype for Business Remote Code Execution Vulnerability
- CVE-2026-69646 Skype for Business Spoofing Vulnerability
- CVE-2026-66307 Skype for Business and Lync Denial of Service Vulnerability
- CVE-2023-36780 Skype for Business Remote Code Execution Vulnerability
Sources
Also known as GHSA-wwcv-p4qq-wm65.