---
id: "CVE-2026-118706"
page: "https://infrastack.ai/live/CVE-2026-118706"
kind: "vulnerability"
aliases: ["CVE-2026-118706"]
title: "Microsoft Excel: use-after-free lets a remote attacker run code"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "other"
products: [{"name": "Microsoft 365 Apps for Enterprise", "fixed": ["Current Channel 2610 20527.20196"], "affected": ">= 16.0.1, below Nov 2026 build (see OfficeSecurityReleases)", "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: ["excel", "file-open", "macos", "microsoft-office", "other", "windows"]
not_affected_if: ["patched-nov-2026"]
published_at: "2026-11-10T19:19:45+00:00"
first_seen_at: "2026-11-10T19:24:52+00:00"
updated_at: "2026-11-10T23:09:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118706", "first_seen_at": "2026-11-10T19:24:52+00:00"}, {"source": "analyst", "url": "https://nvd.nist.gov/vuln/detail/cve-2026-118706", "first_seen_at": "2026-11-10T23:09:42+00:00", "cites": ["https://nvd.nist.gov/vuln/detail/cve-2026-118706", "https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates"]}]
exploit_sources: []
---

# Microsoft Excel: use-after-free lets a remote attacker run code

Link for people: https://infrastack.ai/live/CVE-2026-118706 (this .md is for agents)

A use-after-free bug in Microsoft Office Excel lets an unauthorized attacker run code over a network. The sources give no further detail on the trigger or affected versions.

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

## Affected

- vendor:Microsoft 365 Apps for Enterprise affected >= 16.0.1, below Nov 2026 build (see OfficeSecurityReleases) fixed Current Channel 2610 20527.20196
- 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 Excel: File > Account > About Excel, compare the build number with the fixed builds in Microsoft's Office security update release notes (Nov 10, 2026). Mac: Excel > About Excel, fixed is 16.115.26110837.

## Fix

Update Office to the Nov 10, 2026 build: Current Channel 2610 build 20527.20196 or later; Monthly Enterprise 2610 20527.20194, 2609 20430.20264, 2608 20326.20320; Office LTSC 2024 16.0.17932.21140; LTSC 2021 16.0.14334.21048; Office for Mac 16.115.26110837.

## Timeline

- 2026-11-10T19:24:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118706
- 2026-11-10T23:09:42+00:00 analyst https://nvd.nist.gov/vuln/detail/cve-2026-118706 — Fixed in Nov 10 2026 Office security updates (Learn release notes list CVE under Excel); per-product ranges from Microsoft CNA data via NVD/OpenCVE snippets, MSRC page not readable (JS). Not exploited per sources; UI:R so a file must be opened.

## Documents

- [advisory] NVD CVE-2026-118706 (Microsoft CNA data) https://nvd.nist.gov/vuln/detail/cve-2026-118706
- [fix] Microsoft Office security updates release notes (Nov 10, 2026) https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

## From the sources

Use after free in Microsoft Office Excel 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_