---
id: "CVE-2026-109501"
page: "https://infrastack.ai/live/CVE-2026-109501"
kind: "vulnerability"
aliases: ["CVE-2026-109501"]
title: "Microsoft Word: out-of-bounds read lets a remote attacker run code"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "other"
products: [{"name": "Microsoft Office Word", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "Microsoft 365 Apps for Enterprise", "fixed": ["see aka.ms/OfficeSecurityReleases"], "affected": ">= 16.0.1, below the November 2026 build", "ecosystem": "vendor"}, {"name": "Microsoft Office LTSC 2021", "fixed": ["16.0.14334.21048"], "affected": ">= 16.0.1, < 16.0.14334.21048", "ecosystem": "vendor"}, {"name": "Microsoft Office LTSC 2024", "fixed": ["16.0.17932.21140"], "affected": ">= 16.0.0, < 16.0.17932.21140", "ecosystem": "vendor"}, {"name": "Microsoft Office for Mac", "fixed": ["16.115.26110837"], "affected": "< 16.115.26110837", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["macos", "microsoft-office", "microsoft-word", "other", "user-interaction", "windows"]
not_affected_if: []
published_at: "2026-11-10T19:18:19+00:00"
first_seen_at: "2026-11-10T19:24:25+00:00"
updated_at: "2026-11-11T00:40:41+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109501", "first_seen_at": "2026-11-10T19:24:25+00:00"}, {"source": "analyst", "url": "https://www.cybersecurity-help.cz/vdb/vulns/164752/", "first_seen_at": "2026-11-11T00:40:41+00:00", "cites": ["https://www.cybersecurity-help.cz/vdb/vulns/164752/", "https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates", "https://app.opencve.io/cve/CVE-2026-109501"]}]
exploit_sources: []
---

# Microsoft Word: out-of-bounds read lets a remote attacker run code

Link for people: https://infrastack.ai/live/CVE-2026-109501 (this .md is for agents)

A memory read past the end of a buffer in Microsoft Office Word can be triggered over a network. The sources say an unauthorized attacker can use it to execute code.

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

## Affected

- vendor:Microsoft Office Word affected range not listed fixed no fixed version listed
- vendor:Microsoft 365 Apps for Enterprise affected >= 16.0.1, below the November 2026 build fixed see aka.ms/OfficeSecurityReleases
- vendor:Microsoft Office LTSC 2021 affected >= 16.0.1, < 16.0.14334.21048 fixed 16.0.14334.21048
- vendor:Microsoft Office LTSC 2024 affected >= 16.0.0, < 16.0.17932.21140 fixed 16.0.17932.21140
- vendor:Microsoft Office for Mac affected < 16.115.26110837 fixed 16.115.26110837

## How to check

In any Office app: File > Account > About (Windows) or Word > About Word (Mac). Compare the version against the fixed builds. Affected: Microsoft 365 Apps, Office LTSC 2021 < 16.0.14334.21048, LTSC 2024 < 16.0.17932.21140, Office for Mac / LTSC for Mac 2021/2024 < 16.115.26110837.

## Fix

Install the November 10, 2026 Office security update: Office LTSC 2024 to 16.0.17932.21140 (build 17932.21140), LTSC 2021 to 16.0.14334.21048, Office for Mac / LTSC for Mac to 16.115.26110837, Microsoft 365 Apps to the current builds on aka.ms/OfficeSecurityReleases (Current Channel 2610 build 20527.20196).

## Timeline

- 2026-11-10T19:24:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-109501
- 2026-11-11T00:40:41+00:00 analyst https://www.cybersecurity-help.cz/vdb/vulns/164752/ — MSRC page is JS-only, unreadable; versions from CNA data (via OpenCVE/NVD mirror), UI/PDF-export detail from Cybersecurity Help (secondary). Nothing marked verified. Not exploited, no PoC found.

## Documents

- [describes] Out-of-bounds read in Microsoft Office - CVE-2026-109501 (Cybersecurity Help) https://www.cybersecurity-help.cz/vdb/vulns/164752/
- [fix] Microsoft Office security updates release notes (Nov 10, 2026) https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
- [mentions] OpenCVE CVE-2026-109501 (CNA product data) https://app.opencve.io/cve/CVE-2026-109501

## From the sources

Out-of-bounds read in Microsoft Office Word allows an unauthorized 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_