CVE-2026-66302: Skype for Business Remote Code Execution Vulnerability
External control of file name or path in Skype for Business allows an unauthorized attacker to execute code over a network.
Other sources
Skype for Business Remote Code Execution Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.0.9319.885Patch KB5123301 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 7.0.2046.569Patch KB5123300 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 7.0.2046.879Patch KB5123287
Event History
Frequently Asked Questions
Which deployments are identified as affected?
The affected products listed are Microsoft Skype for Business Server 2015 CU13, Skype for Business Server 2019 CU8, and Skype for Business Server Subscription Edition CU1.
Does exploitation require credentials or user interaction?
No. The CVSS vector indicates network-based exploitation with low attack complexity, no privileges required, and no user interaction required.
What is the potential security impact if exploitation succeeds?
The vulnerability is rated critical with a CVSS score of 9.8 and has high confidentiality, integrity, and availability impacts.