CVE-2026-69646: CWE-347: Improper Verification of Cryptographic Signature in Microsoft Skype for Business Server 2015 CU13
Description
Improper verification of cryptographic signature in Skype for Business allows an unauthorized attacker to perform spoofing over an adjacent network.
CVSS v3.1
Score 8.3high
Affected software
Microsoft
Skype for Business Server 2015 CU13
Microsoft
Skype for Business Server 2019 CU8
Microsoft
Skype for Business Server Subscription Edition CU1
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-69646) in Microsoft Skype for Business Server 2015 CU13 is due to improper verification of cryptographic signatures (CWE-347). It enables an attacker without privileges to spoof communications over an adjacent network. The CVSS 3.1 vector indicates the attack requires adjacent network access, no privileges, and no user interaction, with high impact on confidentiality and integrity and low impact on availability. Microsoft has published an official fix for this issue.
Potential Impact
Successful exploitation allows an attacker on an adjacent network to spoof communications, potentially compromising confidentiality and integrity of data transmitted via Skype for Business Server 2015 CU13. Availability impact is low. There are no known exploits in the wild at this time.
Mitigation Recommendations
An official fix is available from Microsoft. Users should apply the provided patch as detailed in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69646 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-08-03T21:24:59.409Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69646","vendor":"Microsoft"}]
Threat ID: 6aa059e3acd9273b4913eacc
Added to database: 09/08/2026, 18:54:27 UTC
Last enriched: 10/14/2026, 21:42:27 UTC
Last updated: 10/23/2026, 01:15:26 UTC
Views: 106
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