Microsoft Office Word: Heap-based buffer overflow allows remote code execution
Summary
A heap-based buffer overflow in Microsoft Office Word allows an unauthenticated attacker to execute code on the affected system over a network. Exploitation requires the victim to open a crafted document, typically received by email or download, and the attack complexity is rated high. Successful exploitation would give the attacker full control over confidentiality, integrity and availability on the affected endpoint.
Affected
- Microsoft 365 Apps for Enterprise (32- and 64-bit): 16.0.1 before the build listed on the Microsoft security release page (aka.ms/OfficeSecurityReleases)
- Office 365 for Mac: 1.0.0 before 16.115.26110837
- Office LTSC 2021 (32- and 64-bit): 16.0.1 before 16.0.14334.21048
- Office LTSC 2024: 16.0.0 before 16.0.17932.21140 (unconfirmed, third-party listing)
- Office LTSC for Mac 2021 and 2024: 16.0.0 before 16.115.26110837 (unconfirmed, third-party listing)
Fixed in
- Office LTSC 2021: 16.0.14334.21048 (vendor data)
- Office 365 for Mac: 16.115.26110837 (vendor data)
- Microsoft 365 Apps for Enterprise: build not confirmed, see Microsoft security release page
- Office LTSC 2024 (Windows): 16.0.17932.21140 (unconfirmed)
- Office LTSC for Mac: 16.115.26110837 (unconfirmed)
Workaround
Unknown.
Exploitation
- No exploitation in the wild found at the time of research
- No public proof of concept found
- Not found in CISA KEV at the time of research (status unconfirmed)
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total
Our recommendation
- Deploy the November 2026 Office security updates to all endpoints and VDI images as a priority monthly patch
- Verify the installed build against the fixed builds on the MSRC advisory
- Keep Protected View enabled and handle unsolicited Word attachments with care
- Use an email gateway that blocks or sandboxes Office attachments until patching is complete
- Recheck NVD and CISA KEV in the coming days, as the status may change
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 CVE-2026-110053 www.cve.org
- Microsoft Security Update Guide CVE-2026-110053 msrc.microsoft.com
- Strix AI CVE-2026-110053 (third-party listing) www.strix.ai
- 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 11 Nov 2026, 06:02.
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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