Microsoft Skype For Business Server Subscription Edition vulnerabilities

10 CVEs affecting Microsoft Skype For Business Server Subscription Edition, 0 known to be exploited (CISA KEV), with EPSS scores. Latest: CVE-2026-69646, published 2026-09-08.

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

• CVE-2026-66307, published 2026-09-08. High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days. Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network.
• CVE-2026-66308, published 2026-09-08. Medium severity, CVSS 6.5. EPSS: 1.1% chance of exploitation in the next 30 days. Out-of-bounds read in Skype for Business allows an authorized attacker to deny service over a network.
• CVE-2026-66303, published 2026-09-08. Medium severity, CVSS 6.5. EPSS: 1.1% chance of exploitation in the next 30 days. Null pointer dereference in Skype for Business allows an authorized attacker to deny service over a network.
• CVE-2026-66302, published 2026-09-08. Critical severity, CVSS 9.8. EPSS: 1% chance of exploitation in the next 30 days. External control of file name or path in Skype for Business allows an unauthorized attacker to execute code over a network.
• CVE-2026-66304, published 2026-09-08. High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days. Server-side request forgery (ssrf) in Skype for Business allows an unauthorized attacker to disclose information over a network.
• CVE-2026-66306, published 2026-09-08. Medium severity, CVSS 6.5. EPSS: 0.9% chance of exploitation in the next 30 days. Generation of error message containing sensitive information in Skype for Business allows an unauthorized attacker to disclose information over a network.
• CVE-2026-63523, published 2026-09-08. Medium severity, CVSS 6.1. EPSS: 0.6% chance of exploitation in the next 30 days. Improper neutralization of input during web page generation ('cross-site scripting') in Skype for Business allows an unauthorized attacker to perform spoofing over a network.
• CVE-2026-66305, published 2026-09-08. High severity, CVSS 7.1. EPSS: 0.5% chance of exploitation in the next 30 days. Use of client-side authentication in Skype for Business allows an authorized attacker to perform spoofing over a network.
• CVE-2026-69642, published 2026-09-08. Medium severity, CVSS 6.1. EPSS: 0.4% chance of exploitation in the next 30 days. Improper neutralization of input during web page generation ('cross-site scripting') in Skype for Business allows an unauthorized attacker to perform spoofing over a network.
• CVE-2026-69646, published 2026-09-08. High severity, CVSS 8.3. EPSS: 0.3% chance of exploitation in the next 30 days. Improper verification of cryptographic signature in Skype for Business allows an unauthorized attacker to perform spoofing over an adjacent network.