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Vulnerabilities/CVE-2026-85873Public Intelligence Dossier
Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-85873Unknown / EvaluatingImportant (raw)CVSS 6.5CWE-639

Skype for Business Elevation of Privilege Vulnerability

Published: 13 Oct 2026•Last updated: 13 Oct 2026, 12:30 PM IST•Source identifier: secure@microsoft.com
Dossier completeness: source-provided sections 3 / 3 · rule guidance not available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
6.5Important (raw)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Metric sourceMicrosoft MSRC CVRF
EPSS probability
0.8%0.008
Percentile57th
Weakness type
CWE-639
No further CWE recorded
Remediation
Patch status unknown
KB5131692, KB5131693, KB5132779

Why It Matters

Analysis dossier

Why It Matters

Improper authorization in Skype for Business and Microsoft Lync allows an authorized attacker to elevate privileges over a network.

SOC priority

Medium

Actively exploited

No

Publicly disclosed

Unknown

Risk basis: Microsoft or Microsoft-managed product relevance; No confirmed exploitation signal in current enrichment

Affected Products & Remediation

3 source-backed products
Affected products and versions (source)
  • Skype for Business Server Subscription Edition CU1 · version range not provided by source · Microsoft MSRC · Source
  • Skype for Business Server 2019 CU8 · version range not provided by source · Microsoft MSRC · Source
  • Skype for Business Server 2015 CU13 · version range not provided by source · Microsoft MSRC · Source
Recorded patch / KBKB5131692, KB5131693, KB5132779

Vendor or catalog guidance (source)

  • Microsoft MSRC: Install the security update KB5131692 listed by MSRC
  • Microsoft MSRC: Install the security update KB5131693 listed by MSRC
  • Microsoft MSRC: Install the security update KB5132779 listed by MSRC

Known exploitation (source facts)

Only what a source states. Unknown means no source has said either way; it is not "not exploited".

CISA KEV
Unknown
Exploited (source statement)
No
Publicly disclosed (source)
Unknown

Suggested hunting (rule-based inference)

SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.

No rule-based guidance for this vulnerability class

CISA KEV Record

CISA KEV status was not determined for this record.

Change History & Source Data

— No recorded material change

CNA / source
secure@microsoft.com
Record status · verification
UPDATED · Unknown
CPE
Unknown

Evidence & Provenance

3 public sources
api.msrc.microsoft.comSource recordnvd.nist.govSource recordmsrc.microsoft.comSource record
Detection Hunting Query

— No published hunting query names this record. Browse community and library queries instead.

Open KQL Library

Correlated briefings

Microsoft Security Update Guide · Limited verificationOctober 2026 Security UpdatesPublished 13 Oct 2026
SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.