- What: A Spoofing vulnerability is disclosed in Skype for Business
- Impact: Attackers could impersonate users or services
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Privacy Statement Third-Party Cookies AcceptRejectManage cookies MSRC ๎ฌ Customer Guidance ๎ฌ Security Update Guide ๎ฌ Vulnerabilities ๎ฌ CVE-2026-69646 Skype for Business Spoofing Vulnerability New On this page ๎ CVE-2026-69646 ๎ Subscribe RSS PowerShell ๎ฅ API ๎ฅ CSAF Security Vulnerability Released: Sep 8, 2026 Assigning CNA Microsoft CVE.org link CVE-2026-69646 ๏ Impact Spoofing Max Severity Important Weakness CWE-347: Improper Verification of Cryptographic Signature CVSS Source Microsoft Vector String CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L/E:U/RL:O/RC:C Metrics CVSS:3.1 8.3 / 7.2 ๎ฅ Base score metrics: 8.3 / Temporal score metrics: 7.2 ๎ฅฎ Expand all ๎ฅฐ Collapse all Metric Value ๎ฃฌ ๎ฅด Base score metrics(8) Attack Vector Adjacent Attack Complexity Low Privileges Required None User Interaction None Scope Unchanged Confidentiality High Integrity High Availability Low ๎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 Improper verification of cryptographic signature in Skype for Business allows an unauthorized attacker to perform spoofing over an adjacent 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 How could an attacker exploit this vulnerability? An attacker with access to the internal network and a certificate trusted by the deployment could exploit this vulnerability by impersonating a trusted Skype for Business server. Successful exploitation could allow the attacker to act as another user or administrator without Skype credentials or user interaction. Acknowledgements Yogesh Mandge 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 ๎ Edit columns ๎ข Download ๎ Filters ๎ก Product Family ๎ Max Severity ๎ Impact ๎ Platform ๎ ๎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 2015 CU13 - Spoofing Important Title: Knowledge Base Articles for Skype for Business Server 2015 CU13, Content:, 1 link 5123301 ๏ 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 ๏ Title: Download Security Update for Skype for Business Server Subscription Edition CU1, Content:, 1 link Security Update ๏ Title: Build numbers, Content: 7.0.2046.879 Title: Assigning CNA, Content: Microsoft 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 ๏ 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 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. ๎น How satisfied are you with the MSRC Security Update Guide? Rating ๎ Broken ๎ช Bad ๎ Below average ๎ช Average ๎ฎ Great! ๎ข Your Privacy Choices Consumer Health Privacy Privacy & Cookies