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CVE-2026-66305 (GCVE-0-2026-66305)

Vulnerability from cvelistv5 – Published: 2026-09-08 18:32 – Updated: 2026-09-09 19:36
VLAI
Title
Skype for Business Spoofing Vulnerability
Summary
Use of client-side authentication in Skype for Business allows an authorized attacker to perform spoofing over a network.
Severity
7.1 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N/E:U/RL:O/RC:C
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-09 15:49 UTC
CWE
  • CWE-603 - Use of Client-Side Authentication
Assigner
References
Impacted products
Vendor Product Version CPE status
Microsoft Skype for Business Server 2015 CU13 Affected: 9319.0 , < 6.0.9319.885 (custom)
guessed Create a notification for this product.
Microsoft Skype for Business Server 2019 CU8 Affected: 2046.0 , < 7.0.2046.569 (custom)
guessed Create a notification for this product.
Microsoft Skype for Business Server Subscription Edition CU1 Affected: 2046.0 , < 7.0.2046.879 (custom)
guessed Create a notification for this product.
Date Public
2026-09-08 14:00
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.