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Microsoft Security Response CenterCVE-2026-69646

Skype for Business Spoofing Vulnerability

Improper verification of cryptographic signature in Skype for Business allows an unauthorized attacker to perform spoofing over an adjacent network.

Read the vendor bulletin Get alerts for Skype for Business Server 2019 CU8
8.3CVSS out of 10High severity
Scope

What the vendor says is affected

  • Skype for Business Server 2019 CU8
  • Skype for Business Server Subscription Edition CU1
  • Skype for Business Server 2015 CU13

Versions the vendor lists as fixed

  • 7.0.2046.569
  • 7.0.2046.879
  • 6.0.9319.885
Next step

What the vendor recommends

Install KB5123300. Install KB5123287. Install KB5123301.

Review the complete instructions on the vendor's site
Timeline

When this advisory changed

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Added to SecurityAlert

    We collected the advisory from the official source.

  3. Confirmed at the source

    Our collector saw this advisory during a later source check.

Vulnerabilities

CVEs named in this advisory

CVE-2026-69646View CVSS, KEV, EPSS, and threat context
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