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CVE-2026-66305 Skype for Business Spoofing Vulnerability

  • What: A spoofing vulnerability in Skype for Business
  • Impact: Potential for impersonation and unauthorized access
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Privacy Statement Third-Party Cookies AcceptRejectManage cookies MSRC ๎ฌ Customer Guidance ๎ฌ Security Update Guide ๎ฌ Vulnerabilities ๎ฌ CVE-2026-66305 Skype for Business Spoofing Vulnerability New On this page ๎œ CVE-2026-66305 ๎œ• Subscribe RSS PowerShell ๎ฅƒ API ๎ฅƒ CSAF Security Vulnerability Released: Sep 8, 2026 Assigning CNA Microsoft CVE.org link CVE-2026-66305 ๏Ÿ Impact Spoofing Max Severity Important Weakness CWE-603: Use of Client-Side Authentication CVSS Source Microsoft Vector String CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N/E:U/RL:O/RC:C Metrics CVSS:3.1 7.1 / 6.2 ๎ฅ† Base score metrics: 7.1 / Temporal score metrics: 6.2 ๎ฅฎ Expand all ๎ฅฐ Collapse all Metric Value ๎ฃฌ ๎ฅด Base score metrics(8) Attack Vector Network Attack Complexity Low Privileges Required Low User Interaction None Scope Unchanged Confidentiality Low Integrity High Availability None ๎ฃฌ ๎ฅด Temporal score metrics(3) Exploit Code Maturity Unproven Remediation Level Official Fix Report Confidence Confirmed Please see Common Vulnerability Scoring System for more information on the definition of these metrics. Executive Summary Use of client-side authentication in Skype for Business allows an authorized attacker to perform spoofing over a network. Exploitability The following table provides an exploitability assessment for this vulnerability at the time of original publication. Publicly disclosed No Exploited No Exploitability assessment Exploitation Less Likely FAQ According to the CVSS metric, successful exploitation of this vulnerability could lead to a total loss of integrity (I:H). What does that mean for this vulnerability? An attacker who successfully exploited this vulnerability could inject content that appears to come from a trusted source, causing the affected application to display spoofed or manipulated content to the user. Acknowledgements Manish Kumar Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information. Security Updates To determine the support lifecycle for your software, see the Microsoft Support Lifecycle. Release date Descending ๎œ Edit columns ๎ข– Download ๎œœ Filters ๎œก Product Family ๎œ Max Severity ๎œ Impact ๎œ Platform ๎œ ๎ข” Clear Release date ๎นฉ Product Platform Impact Max Severity Article Download Build Number Assigning CNA Title: Release date, Content: Sep 8, 2026 Skype for Business Server 2019 CU8 - Spoofing Important Title: Knowledge Base Articles for Skype for Business Server 2019 CU8, Content:, 1 link 5123300 ๏Ÿ Title: Download Security Update for Skype for Business Server 2019 CU8, Content:, 1 link Security Update Title: Build numbers, Content: 7.0.2046.569 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Sep 8, 2026 Skype for Business Server 2015 CU13 - Spoofing Important Title: Knowledge Base Articles for Skype for Business Server 2015 CU13, Content:, 1 link 5123301 ๏Ÿ Title: Download Security Update for Skype for Business Server 2015 CU13, Content:, 1 link Security Update Title: Build numbers, Content: 6.0.9319.885 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Sep 8, 2026 Skype for Business Server Subscription Edition CU1 - Spoofing Important Title: Knowledge Base Articles for Skype for Business Server Subscription Edition CU1, Content:, 1 link 5123287 ๏Ÿ Title: Download Security Update for Skype for Business Server Subscription Edition CU1, Content:, 1 link Security Update ๏Ÿ Title: Build numbers, Content: 7.0.2046.879 Title: Assigning CNA, Content: Microsoft All results loaded Loaded all 3 rows Disclaimer The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. Revisions version revisionDate description 1.0 Sep 8, 2026 Information published. ๎žน How satisfied are you with the MSRC Security Update Guide? Rating ๎žƒ Broken ๎ชˆ Bad ๎— Below average ๎ช‡ Average ๎ฎ Great! ๎ข” Your Privacy Choices Consumer Health Privacy Privacy & Cookies

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