CVE-2026-66305

Use of client-side authentication in Skype for Business allows an authorized attacker to perform spoofing over a network.

CVSS v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66305	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:microsoft:skype_for_business_server:2015:cumulative_update_13::::::
	cpe:2.3:a:microsoft:skype_for_business_server:2015:cumulative_update_13_hotfix_2::::::

Configuration 2 (hide)

OR	cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8::::::
	cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8_hotfix1::::::
	cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8_hotfix2::::::

Configuration 3 (hide)

cpe:2.3:a:microsoft:skype_for_business_server_subscription_edition:7.0.2046.849:*:*:*:*:*:*:*

History

16 Sep 2026, 19:24

Type	Values Removed	Values Added
References	~~() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66305 -~~	() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66305 - Patch, Vendor Advisory
First Time		Microsoft Microsoft skype For Business Server Subscription Edition Microsoft skype For Business Server
CPE		cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8:::::: cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8_hotfix1:::::: cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8_hotfix2:::::: cpe:2.3:a:microsoft:skype_for_business_server:2015:cumulative_update_13_hotfix_2:::::: cpe:2.3:a:microsoft:skype_for_business_server:2015:cumulative_update_13:::::: cpe:2.3:a:microsoft:skype_for_business_server_subscription_edition:7.0.2046.849:::::::*

Information

Published : 2026-09-08 19:18

Updated : 2026-09-16 19:24

NVD link : CVE-2026-66305

Mitre link : CVE-2026-66305

CVE.ORG link : CVE-2026-66305

JSON object : View

Products Affected

microsoft

skype_for_business_server
skype_for_business_server_subscription_edition

CWE

CWE-603

Use of Client-Side Authentication

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