Microsoft Office Word: Heap-based buffer overflow enables remote code execution
Summary
Microsoft Office Word contains a heap-based buffer overflow (CWE-122). An unauthorized attacker can execute code remotely. The record describes the attack as network-based and requiring no privileges, but user interaction is required, so a user must typically open a manipulated document. CVSS 3.1 base score is 8.8 (High).
Affected
- Microsoft 365 Apps for Enterprise: from 16.0.1 before the fixed 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 stated in the record retrieved
- 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
- Office LTSC 2021: 16.0.14334.21048
- Office for Mac and LTSC for Mac: 16.115.26110837
- Microsoft 365 Apps and LTSC 2024: unknown from the vendor record; a third-party source gives 16.0.17932.21140 for LTSC 2024, which is unverified and must be checked in the MSRC advisory
Workaround
No workaround known. Install the November 2026 Office security update.
Exploitation
- No exploitation in the wild known.
- CVSS vector E:U/RL:O/RC:C: exploit maturity 'Unproven'.
- No public proof of concept found.
- CISA SSVC: exploitation none, automatable no, technical impact total.
Our recommendation
- Patch all Office clients (Microsoft 365 Click-to-Run, Mac and LTSC) in the November 2026 cycle, with priority.
- Verify installed build numbers against the MSRC advisory after patching.
- Where patching is delayed, restrict opening of untrusted Office attachments.
- Monitor for exploitation activity affecting Office documents.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-116719 msrc.microsoft.com
- CVE.org record CVE-2026-116719 www.cve.org
- Strix CVE-2026-116719 (unverified) www.strix.ai
- Qualys: Microsoft Patch Tuesday November 2026 blog.qualys.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, 22:40.
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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