Microsoft Office Word: Heap-based buffer overflow leads to remote code execution
Summary
A heap-based buffer overflow in Microsoft Office Word allows an unauthenticated attacker to execute code over a network. The attack requires that a user opens a crafted document, for example one delivered by email or download. The CVSS base score is 8.8 (HIGH), and the CISA SSVC assessment rates the technical impact as total.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the first fixed build (exact build unknown, see MSRC)
- Microsoft Office 365 for Mac: 1.0.0 to before 16.115.26110837
- Microsoft Office LTSC 2021 (Windows): 16.0.1 to before 16.0.14334.21048
- Microsoft Office LTSC 2024 (Windows): 16.0.0 to before 16.0.17932.21140
- Microsoft Office LTSC for Mac 2021: 16.0.1 to before 16.115.26110837
- Microsoft Office LTSC for Mac 2024: 16.0.0 to before 16.115.26110837 (unconfirmed)
Fixed in
- Office 365 for Mac and LTSC for Mac: 16.115.26110837 (per third-party aggregator, verify on MSRC)
- Office LTSC 2021 (Windows): 16.0.14334.21048 (per third-party aggregator, verify on MSRC)
- Office LTSC 2024 (Windows): 16.0.17932.21140 (per third-party aggregator, verify on MSRC)
- Microsoft 365 Apps for Enterprise: Unknown. See https://aka.ms/OfficeSecurityReleases
Workaround
Unknown. No vendor workaround was found. Patching is the primary fix.
Exploitation
- No evidence of exploitation in the wild found at the time of writing.
- No public proof of concept found.
- CISA KEV status not checked.
- NVD analysis pending.
Our recommendation
- Confirm the exact fixed builds on the MSRC advisory and compare them with the installed versions.
- Patch Office installations that receive email attachments with priority, including Microsoft 365 Apps, LTSC and Office 2024 perpetual installs.
- Keep Protected View enabled and block or quarantine Office attachments from unknown senders as an interim measure.
- Check the CISA KEV catalog and monitor for a public proof of concept.
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-2026-112722 msrc.microsoft.com
- CVE Record CVE-2026-112722 www.cve.org
- Strix aggregator: CVE-2026-112722 (third-party, unverified) www.strix.ai
- Qualys review of November 2026 Patch Tuesday 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, 23:01.
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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