Microsoft SharePoint Server: Privilege escalation via code injection
Summary
Microsoft SharePoint Server Subscription Edition (on-premises) contains a code injection flaw (CWE-94) that lets an authorized attacker elevate privileges over the network. The attacker needs a valid low-privilege account, and no user interaction is required. CVSS 8.8 (High); at the time of review, no confirmed exploitation and no public exploit were found.
Affected
- SharePoint Server Subscription Edition: 16.0.0 to before 16.0.20326.20190 (lower bound not confirmed by Microsoft)
- Classic SharePoint versions (2016/2019) and Workflow Manager: Unknown.
Fixed in
- SharePoint Server Subscription Edition build 16.0.20326.20190 via Microsoft KB5002927 (October 13, 2026 update)
Workaround
- No vendor workaround specific to this CVE found. The cumulative update is the only known fix.
- Check the MSRC page for official interim guidance.
Exploitation
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
- No confirmed exploitation in the wild found; CISA KEV: not listed.
- No public proof-of-concept found.
- EPSS about 0.9 to 2.0 percent, depending on source.
Our recommendation
- Patch SharePoint Server Subscription Edition with KB5002927 within the normal monthly cycle, sooner if the server is internet-facing or has many accounts.
- If SharePoint Workflow Manager is used, install KB5002799 first.
- Review user accounts, guest and external access, and access rights.
- Check whether the server is reachable from the internet and monitor for unusual privilege changes or code execution on the server.
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-2026-102863 msrc.microsoft.com
- Microsoft KB5002927 SharePoint update support.microsoft.com
- NVD record via Vulners vulners.com
- Strix CVE-2026-102863 www.strix.ai
- Senserva KB5002927 senserva.com
- Qualys October 2026 Patch Tuesday review blog.qualys.com
- BDU FSTEC BDU:2026-16772 vulners.com
- Microsoft Security Bulletin MS:CVE-2026-102863 via Vulners vulners.com
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, 19:28.
Original description (NVD)
Improper control of generation of code ('code injection') 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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