Microsoft Skype For Business Server 2015 CU13 vulnerabilities

3 CVEs affecting Microsoft Skype For Business Server 2015 CU13, 0 known to be exploited (CISA KEV), with EPSS scores. Latest: CVE-2026-85873, published 2026-10-13.

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Known exploited (CISA KEV) first, then by EPSS exploit probability.

• CVE-2026-70297, published 2026-10-13. High severity, CVSS 8.8. EPSS: 1% chance of exploitation in the next 30 days. Absolute path traversal in Skype for Business and Microsoft Lync allows an authorized attacker to execute code over a network.
• CVE-2026-83746, published 2026-10-13. High severity, CVSS 8.1. EPSS: 1% chance of exploitation in the next 30 days. Absolute path traversal in Skype for Business and Microsoft Lync allows an authorized attacker to elevate privileges over a network.
• CVE-2026-85873, published 2026-10-13. Medium severity, CVSS 6.5. EPSS: 0.8% chance of exploitation in the next 30 days. Improper authorization in Skype for Business and Microsoft Lync allows an authorized attacker to elevate privileges over a network.