CVE-2026-66306 Skype for Business Information Disclosure Vulnerability

Medium 6.5 Published Updated

An unauthorized attacker can disclose sensitive information via error messages in Skype for Business Server.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2026-66306?

CVE-2026-66306 is a medium-severity 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, and only if a user opens a file or follows a link.

Official description

Generation of error message containing sensitive information in Skype for Business allows an unauthorized attacker to disclose information over a network.

Weakness: CWE-209

Which versions are affected by CVE-2026-66306?

It affects 2 products.

Products include Microsoft Skype for Business Server, Microsoft Skype for Business Server Subscription Edition.

How do I fix CVE-2026-66306?

No fix has been published for CVE-2026-66306 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-66306 being exploited?

There is no known exploitation of CVE-2026-66306 in the wild and no public exploit code.

Sources

Also known as GHSA-f56r-qvv6-jr8m.

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