Vulnerability in Microsoft Skype For Business Server

CVE-2026-69646

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

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.003 (23.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 23.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-69646: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-69646?
CVE-2026-69646 is a high-severity vulnerability in Microsoft Skype For Business Server, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.3/10. Published 2026-09-08.
How severe is CVE-2026-69646?
High severity. CVSS v3 base score is 8.3 out of 10.