CVE-2026-66307 PUBLISHED

Skype for Business and Lync Denial of Service Vulnerability

Assigner: microsoft
Reserved: 24.07.2026 Published: 08.09.2026 Updated: 08.09.2026

Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
CVSS Score: 7.5

Product Status

Vendor Microsoft
Product Skype for Business Server 2015 CU13
Versions
  • affected from 9319.0 to 6.0.9319.885 (excl.)
Vendor Microsoft
Product Skype for Business Server 2019 CU8
Versions
  • affected from 2046.0 to 7.0.2046.569 (excl.)
Vendor Microsoft
Product Skype for Business Server Subscription Edition CU1
Versions
  • affected from 2046.0 to 7.0.2046.879 (excl.)

References

Problem Types