Microsoft Office: Heap-based buffer overflow enables remote code execution
Summary
A heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network. The attack requires user interaction, most likely by opening a malicious document. Impact on confidentiality, integrity and availability is rated high (CVSS 3.1 8.8). NVD analysis was still pending when the record was published.
Affected
- Microsoft 365 Apps for Enterprise (from 16.0.1; exact build range to be confirmed on MSRC)
- Office 365 for Mac: before 16.115.26110837
- Office LTSC 2021: before 16.0.14334.21048
- Office LTSC 2024: before 16.0.17932.21140
- Office LTSC for Mac 2021: before 16.115.26110837
- Office LTSC for Mac 2024: before 16.115.26110837
Fixed in
- Listed versions per the CNA record are the first fixed builds (to be confirmed on MSRC).
- Microsoft 365 Apps for Enterprise: Unknown.
Workaround
Unknown. No vendor or third-party workaround identified; patching is the expected remedy.
Exploitation
- Unknown. No reports of in-the-wild exploitation or public proof-of-concept code found.
- CISA SSVC: exploitation none, automatable no, technical impact total.
Our recommendation
- Install the Microsoft Office security updates for your update channel now and confirm the build numbers on the MSRC page.
- Keep Protected View and macro restrictions enabled.
- Filter risky attachments at the mail gateway and prioritise systems that receive external documents.
- Verify that Microsoft 365/Office update channels are installing automatically.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-116717 msrc.microsoft.com
- Strix: CVE-2026-116717 (third-party aggregator, unverified) 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, 22:41.
Original description (NVD)
Heap-based buffer overflow in Microsoft Office 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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