---
id: "CVE-2026-109464"
page: "https://infrastack.ai/live/CVE-2026-109464"
kind: "vulnerability"
aliases: ["CVE-2026-109464"]
title: "SharePoint Server Subscription Edition: deserialization flaw lets a logged-in user run code (fixed in KB5002945)"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "vendor"
products: [{"name": "Microsoft SharePoint Server Subscription Edition", "fixed": ["16.0.20326.20278"], "affected": ">= 16.0.0, < 16.0.20326.20278", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["authenticated", "microsoft-office", "on-premises", "self-hosted", "sharepoint", "vendor"]
not_affected_if: ["managed-hosting", "sharepoint-online"]
published_at: "2026-11-10T19:18:15+00:00"
first_seen_at: "2026-11-10T19:24:24+00:00"
updated_at: "2026-11-11T00:45:15+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109464", "first_seen_at": "2026-11-10T19:24:24+00:00"}, {"source": "analyst", "url": "https://cveawg.mitre.org/api/cve/CVE-2026-109464", "first_seen_at": "2026-11-11T00:45:15+00:00", "cites": ["https://cveawg.mitre.org/api/cve/CVE-2026-109464", "https://blog.stefan-gossner.com/2026/11/10/sharepoint-security-fixes-released-with-november-2026-pu-and-offered-through-microsoft-update/", "https://support.microsoft.com/help/5002945"]}]
exploit_sources: []
---

# SharePoint Server Subscription Edition: deserialization flaw lets a logged-in user run code (fixed in KB5002945)

Link for people: https://infrastack.ai/live/CVE-2026-109464 (this .md is for agents)

Deserialization of untrusted data (CWE-502) in SharePoint Server Subscription Edition lets an authenticated attacker execute code over the network. CVSS 8.8, Microsoft rates it Important. Not known to be exploited.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Microsoft SharePoint Server Subscription Edition affected >= 16.0.0, < 16.0.20326.20278 fixed 16.0.20326.20278

## How to check

On each SharePoint Server Subscription Edition farm, check the build number (Central Administration > Upgrade and Migration > Check product and patch installation status, or (Get-SPFarm).BuildVersion). Builds below 16.0.20326.20278 are vulnerable.

## Fix

Install KB5002945 (SharePoint Server Subscription Edition, November 10 2026), build 16.0.20326.20278, via Microsoft Update, the Update Catalog or the Download Center.

## Timeline

- 2026-11-10T19:24:24+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-109464
- 2026-11-11T00:45:15+00:00 analyst https://cveawg.mitre.org/api/cve/CVE-2026-109464 — CVE record (Microsoft CNA) and KB5002945 read: SharePoint Server Subscription Edition < 16.0.20326.20278 affected, fixed by KB5002945 (Nov 10 2026). MSRC page not readable by tools. No exploitation (CISA SSVC: none), no PoC. Only Subscription Edition confirmed; SharePoint 2019/2016 not listed.

## Documents

- [advisory] CVE record CVE-2026-109464 (CNA: Microsoft) https://cveawg.mitre.org/api/cve/CVE-2026-109464
- [describes] SharePoint security fixes released with November 2026 PU https://blog.stefan-gossner.com/2026/11/10/sharepoint-security-fixes-released-with-november-2026-pu-and-offered-through-microsoft-update/
- [fix] KB5002945: SharePoint Server Subscription Edition security update, Nov 10 2026 https://support.microsoft.com/help/5002945

## From the sources

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_