Microsoft Office Word: Remote code execution via heap-based buffer overflow
Summary
Microsoft Office Word contains a heap-based buffer overflow (CWE-122). An unauthenticated attacker can execute code over the network if a user opens a crafted file, for example one received by email or downloaded from a file share. The CVSS vector rates confidentiality, integrity and availability as high, and code runs with the rights of the logged-in user. Microsoft has published fixes; no exploitation has been reported.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the fixed build (exact build unknown, see MSRC advisory)
- Microsoft Office 365 for Mac: 1.0.0 before 16.115.26110837
- Microsoft Office LTSC 2021: 16.0.1 before 16.0.14334.21048
- Microsoft Office LTSC 2024: 16.0.0 up to the fixed build (see Fixed)
- Microsoft Office LTSC for Mac 2021: 16.0.1 before 16.115.26110837
- Microsoft Office LTSC for Mac 2024: 16.0.0 before 16.115.26110837
Fixed in
- Microsoft 365 Apps for Enterprise: Unknown (listed only as a link to Microsoft's release page)
- Microsoft Office 365 for Mac: 16.115.26110837
- Microsoft Office LTSC 2021: 16.0.14334.21048
- Microsoft Office LTSC 2024: Unknown from the vendor record; a third-party aggregator lists 16.0.17932.21140, which is unverified
- Microsoft Office LTSC for Mac 2021 and 2024: 16.115.26110837
Workaround
Unknown. No workaround is documented in the sources. Update the affected builds.
Exploitation
- Exploited in the wild: no evidence found
- Public proof of concept: no evidence found
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total
Our recommendation
- Install the Microsoft security updates for Microsoft 365 Apps, Office LTSC 2021/2024 and Office for Mac as soon as possible
- Confirm the installed build numbers against the MSRC advisory
- Block or quarantine untrusted Office attachments at the mail gateway until patched
- Keep Protected View enabled and restrict macros
- Limit local administrator rights and re-check exploitation status (CISA KEV, MSRC) over the coming weeks
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE record (CNA: Microsoft) www.cve.org
- MSRC Security Update Guide advisory msrc.microsoft.com
- Third-party aggregator (unverified LTSC 2024 build) www.strix.ai
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, 23:07.
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.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.