---
id: "CVE-2026-119996"
page: "https://infrastack.ai/live/CVE-2026-119996"
kind: "vulnerability"
aliases: ["CVE-2026-119996"]
title: "Microsoft Outlook: heap buffer overflow lets a network attacker run code"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "other"
products: [{"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 365 Apps for Enterprise", "fixed": ["see https://aka.ms/OfficeSecurityReleases"], "affected": ">= 16.0.1, below the Nov 10 2026 build", "ecosystem": "vendor"}]
ecosystems: []
tags: ["microsoft-365", "microsoft-office", "other", "outlook", "windows"]
not_affected_if: []
published_at: "2026-11-10T19:20:25+00:00"
first_seen_at: "2026-11-10T19:25:07+00:00"
updated_at: "2026-11-10T22:08:15+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119996", "first_seen_at": "2026-11-10T19:25:07+00:00"}, {"source": "analyst", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119996", "first_seen_at": "2026-11-10T22:08:15+00:00", "cites": ["https://nvd.nist.gov/vuln/detail/CVE-2026-119996", "https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates"]}]
exploit_sources: []
---

# Microsoft Outlook: heap buffer overflow lets a network attacker run code

Link for people: https://infrastack.ai/live/CVE-2026-119996 (this .md is for agents)

Heap-based buffer overflow (CWE-122) in Microsoft Office Outlook lets an unauthenticated attacker run code over a network. Microsoft rates it CVSS 7.5 (high complexity, user interaction required). Fixed in the November 10, 2026 Office security updates. No exploitation reported.

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

## Affected

- 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 365 Apps for Enterprise affected >= 16.0.1, below the Nov 10 2026 build fixed see https://aka.ms/OfficeSecurityReleases

## How to check

In Outlook (classic) go to File > Office Account > About Outlook and compare the build to the fixed builds: LTSC 2021 < 16.0.14334.21048, LTSC 2024 < 16.0.17932.21140, Microsoft 365 Apps below the Nov 10 2026 build for your channel.

## Fix

Update Office to the November 10, 2026 build: Current Channel 2610 (20527.20196); Office LTSC 2024 16.0.17932.21140; Office LTSC 2021 16.0.14334.21048; Microsoft 365 Apps per https://aka.ms/OfficeSecurityReleases.

## Timeline

- 2026-11-10T19:25:07+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-119996
- 2026-11-10T22:08:15+00:00 analyst https://nvd.nist.gov/vuln/detail/CVE-2026-119996 — Microsoft's Nov 10 2026 Office release notes list this CVE under Outlook; affected/fixed builds taken from Microsoft CNA data in NVD. MSRC page is JS-only and could not be read; preview-pane/open requirement unconfirmed (CVSS says UI:R, AC:H). No exploitation or PoC found; not in KEV.

## Documents

- [describes] NVD CVE-2026-119996 (Microsoft CNA data) https://nvd.nist.gov/vuln/detail/CVE-2026-119996
- [fix] Microsoft Office security updates release notes (Nov 10, 2026) https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

## From the sources

Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.

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