Microsoft Office Word: Remote code execution via heap-based buffer overflow
Summary
A heap-based buffer overflow in Microsoft Word allows an unauthenticated attacker to execute code over the network. Exploitation requires a user to interact, typically by opening a crafted document received by email or download. The CVSS 3.1 score is 8.8 (High), and NVD analysis was still pending at publication.
Affected
- Microsoft 365 Apps for Enterprise: from 16.0.1 before the build listed at https://aka.ms/OfficeSecurityReleases
- Office 365 for Mac: from 1.0.0 before 16.115.26110837
- Office LTSC 2021: from 16.0.1 before 16.0.14334.21048
- Office LTSC 2024: from 16.0.0 (fixed build not confirmed in the retrieved CVE record)
- Office LTSC for Mac 2021: from 16.0.1 before 16.115.26110837
- Office LTSC for Mac 2024: from 16.0.0 before 16.115.26110837
Fixed in
- Microsoft 365 Apps for Enterprise: Unknown. Check the vendor release page at https://aka.ms/OfficeSecurityReleases
- Office 365 for Mac: 16.115.26110837
- Office LTSC 2021: 16.0.14334.21048
- Office LTSC 2024: 16.0.17932.21140 (secondary source, not confirmed against MSRC)
- Office LTSC for Mac 2021 and 2024: 16.115.26110837
Workaround
Unknown. No vendor-published interim mitigation was found. Install the security update, which is the remedy.
Exploitation
- No evidence of exploitation in the wild at publication.
- CISA SSVC assessment: Exploitation none, Automatable no, Technical Impact total.
- No public proof of concept found.
- The actively exploited zero-day in the same Patch Tuesday release is a separate Outlook spoofing flaw, not this CVE.
Our recommendation
- Patch Microsoft Office on all endpoints in the next maintenance window.
- Check the fixed build for each product, especially Microsoft 365 Click-to-Run and LTSC 2024, rather than relying on the generic link.
- Remind staff to be cautious with documents from unknown senders.
- Monitor the NVD and MSRC entries for changes to the CVSS data and exploitation status.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE.org CVE Record CVE-2026-111285 www.cve.org
- Microsoft Security Update Guide CVE-2026-111285 msrc.microsoft.com
- Strix CVE-2026-111285 (secondary, LTSC 2024 build) www.strix.ai
- Qualys Patch Tuesday November 2026 review blog.qualys.com
- Cybersecurity News: Microsoft November 2026 Patch Tuesday cybersecuritynews.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, 23:41.
Original description (NVD)
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized 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.
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