Microsoft SharePoint Server: Privilege escalation due to missing authorization
Summary
Missing authorization in Microsoft Office SharePoint Server Subscription Edition allows an attacker to elevate privileges over the network. Microsoft's own description assumes an authorized attacker, while the CVSS vector (PR:L) assumes low privileges are required. Third-party reports describe it as possibly reachable without a login, which has not yet been confirmed by Microsoft. Exposure is mainly a concern for farms reachable from the internet or untrusted networks.
Affected
- Microsoft SharePoint Server Subscription Edition (on-premises): versions 16.0.0 to below 16.0.20326.20190
- SharePoint Server 2016 and 2019: unknown, not confirmed
Fixed in
- Build 16.0.20326.20190 via KB 5002927 (released October 13, 2026)
- The release version of Subscription Edition must already be installed
Workaround
Unknown.
Exploitation
- No confirmed in-the-wild exploitation found
- No public proof-of-concept found
- CISA SSVC: exploitation none, automatable no, technical impact total
- Not listed in CISA KEV (per strix.ai record)
- EPSS low (about 0.7% to 2.0%, sources differ)
Our recommendation
- Install KB 5002927 (build 16.0.20326.20190) promptly on all Subscription Edition servers in the farm
- Verify that every server in the farm reaches the fixed build
- Check whether SharePoint is published to the internet or reachable from untrusted networks, and restrict access
- Check whether any SharePoint 2016 or 2019 systems are in scope and verify this on the MSRC page
- Monitor for public proof-of-concept code or a KEV listing
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Microsoft Office SharePoint
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Microsoft Office
- Updates (KB)
- KB5002927
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-102861 msrc.microsoft.com
- Microsoft Support: SharePoint hotfix KB 5002927 support.microsoft.com
- Microsoft Learn: SharePoint updates learn.microsoft.com
- Vulners NVD mirror: CVE-2026-102861 vulners.com
- Senserva: KB 5002927 senserva.com
- VulDB: CVE-2026-102861 vuldb.com
- Positive Technologies: PT-2026-118162 vulners.com
- Strix: CVE-2026-102861 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 19:27.
Original description (NVD)
Missing authorization in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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