Microsoft SharePoint Server: Remote code execution via deserialization of untrusted data
Summary
Deserialization of untrusted data in Microsoft Office SharePoint allows code execution on the server over the network. According to the CVE record, an attacker needs a valid low-privilege account and no user interaction, and could gain full control of the server (CVSS 3.1: 8.8). No exploitation is known at publication.
Affected
- Microsoft SharePoint Server Subscription Edition: 16.0.0 before 16.0.20326.20278 (per CVE record)
- SharePoint Server 2019 and 2016: Unknown. Check the MSRC advisory.
Fixed in
- SharePoint Server Subscription Edition: 16.0.20326.20278 (per CVE record; confirm on MSRC before patching)
- Other product lines: Unknown.
Workaround
- No CVE-specific workaround known. Patching is the fix.
- Until patched, follow general CISA SharePoint hardening guidance: do not expose SharePoint servers directly to the internet, block external access to Central Administration, and verify that AMSI integration is enabled for each web application.
Exploitation
- Exploited in the wild: No evidence found at publication.
- CISA KEV: Not listed as of 2026-11-10.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
- Public proof of concept: Unknown / none found.
Our recommendation
- Identify all on-premises SharePoint servers and their product line and build.
- Check the MSRC advisory and KB article for each product line and apply the fixed build.
- Remove direct internet exposure of SharePoint where possible and restrict Central Administration to internal management networks.
- Review accounts with SharePoint access and disable unused accounts, especially guest and low-privilege accounts.
- Monitor MSRC and CISA KEV over the coming days, as the status may change.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Remote code execution – Microsoft Office SharePoint
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Microsoft Office
- Updates (KB)
- KB5002945
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-109472 msrc.microsoft.com
- CVE.org Record CVE-2026-109472 www.cve.org
- CISA: SharePoint hardening alert (July 2026) www.cisa.gov
- Resecurity: July 2026 SharePoint attacks analysis www.resecurity.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 10 Nov 2026, 23:56.
Original description (NVD)
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code 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.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.