Microsoft Office Word: Remote code execution via heap-based buffer overflow
Summary
A heap-based buffer overflow in Microsoft Office Word allows an unauthenticated attacker to execute code on a vulnerable system over the network. Exploitation requires that a user opens or otherwise processes a malicious document, for example one received by email. The CVSS base score is 8.8 (High). CISA SSVC data rates exploitation as none, and no public exploit was found.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the fixed build (exact build unknown)
- Office 365 for Mac: versions before 16.114.26101123
- Office LTSC 2021: versions before 16.0.14334.20974
- Office LTSC 2024: versions before 16.0.17932.21056
- Office LTSC for Mac 2021 and 2024: versions before 16.114.26101123
Fixed in
- Office LTSC 2021: 16.0.14334.20974
- Office LTSC 2024: 16.0.17932.21056
- Office 365 for Mac and Office LTSC for Mac: 16.114.26101123
- Microsoft 365 Apps for Enterprise (Windows): Unknown. See the Office security release page https://aka.ms/OfficeSecurityReleases
Workaround
- No vendor-documented workaround found.
- Installing the fixed build is the required remediation.
- General hardening: keep Protected View enabled and restrict macros and untrusted attachments.
Exploitation
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, automatable no.
- EPSS below 1%.
- No public proof of concept found.
Our recommendation
- Patch Microsoft 365 Apps and Office LTSC clients to the fixed builds, prioritising clients that process external email.
- Confirm the fixed build for Microsoft 365 Apps for Enterprise on MSRC and the Office security release page.
- Keep Protected View enabled and restrict macros and untrusted attachments.
- Monitor for public exploits and CISA KEV listing.
Information from Microsoft (Patch Tuesday October 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-108441 msrc.microsoft.com
- OpenCVE: CVE-2026-108441 app.opencve.io
- ThreatInt: CVE-2026-108441 cve.threatint.com
- OffSeq Radar: CVE-2026-108441 radar.offseq.com
- Office-Watch: October 2026 Patch Tuesday Office fixes office-watch.com
- CrowdStrike: Patch Tuesday analysis October 2026 www.crowdstrike.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 31 Oct 2026, 16:22.
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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