Microsoft SharePoint Server: Elevation of privilege due to incorrect authorization
Summary
An incorrect authorization check in Microsoft Office SharePoint allows an authenticated attacker to elevate privileges over the network. The CVSS vector requires only a low-privilege account and no user interaction. The risk is highest for internet-facing or broadly accessible SharePoint servers.
Affected
- Microsoft SharePoint Server Subscription Edition: 16.0.0 to before 16.0.20326.20190
- Other SharePoint editions (2016, 2019): Unknown.
Fixed in
- Subscription Edition: build 16.0.20326.20190 or later, included in the October 2026 cumulative update (KB5002927)
- Other editions: Unknown. Check the MSRC advisory.
Workaround
- No vendor workaround known.
- Restrict low-privilege SharePoint accounts and review permissions (general measures, not verified Microsoft guidance).
Exploitation
- CISA SSVC: exploitation none, automatable no, technical impact total.
- Not listed in CISA KEV according to the sources reviewed.
- No evidence of in-the-wild exploitation or public proof of concept found.
- EPSS about 0.007 (low).
Our recommendation
- Apply the October 2026 SharePoint cumulative update (KB5002927) as a priority, especially on internet-facing servers.
- Check which SharePoint editions and build numbers you run and confirm the fix for your edition in the MSRC advisory.
- Review accounts with SharePoint access and remove unneeded rights.
- Monitor logs for unusual privilege changes.
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
- MSRC Security Update Guide: CVE-2026-102862 msrc.microsoft.com
- Microsoft KB5002927 SharePoint Server Subscription Edition support.microsoft.com
- NVD record via Vulners vulners.com
- Vulnrichment (SSVC and EPSS) via Vulners vulners.com
- Strix CVE summary 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)
Incorrect 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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