Microsoft Office Word: Information disclosure via out-of-bounds read
Summary
A out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network. Microsoft states that an attacker could potentially read small portions of heap memory. The attacker must get a user to open a crafted document, so the realistic delivery routes are email and file-sharing. Microsoft rates the impact as confidentiality only, with no code execution.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the fix referenced at aka.ms/OfficeSecurityReleases (fixed build unknown)
- Microsoft Office 365 for Mac: 1.0.0 to before 16.115.26110837
- Microsoft Office LTSC 2021: 16.0.1 to before 16.0.14334.21048
- Microsoft Office LTSC 2024: 16.0.0 to before 16.0.17932.21140 (from a third-party source, not confirmed by Microsoft)
- 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
Fixed in
- Microsoft Office 365 for Mac: 16.115.26110837
- Microsoft Office LTSC 2021: 16.0.14334.21048
- Microsoft 365 Apps for Enterprise: Unknown (check the Microsoft release notes)
- Microsoft Office LTSC 2024: 16.0.17932.21140 (unverified, check the MSRC advisory)
- Patches released on 10 November 2026
Workaround
Unknown. No workaround or mitigation was found in the available sources. Patching is the only documented remedy.
Exploitation
- CISA SSVC: no exploitation known, not automatable
- Rapid7 (November 2026): 'Exploitation Less Likely', not publicly disclosed
- No public proof of concept known
Our recommendation
- Install the November 2026 Office security updates on all Microsoft 365, LTSC and Mac installations, prioritizing users who regularly open external documents
- Verify the fixed build numbers on the MSRC advisory, especially for Microsoft 365 Apps and LTSC 2024
- Warn users about unsolicited documents from email and file-sharing links
- Monitor for unusual Office behavior until patching is complete
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-2026-110066 msrc.microsoft.com
- CVE Record CVE-2026-110066 (CVE.org) www.cve.org
- Rapid7: Patch Tuesday November 2026 www.rapid7.com
- GBHackers: Microsoft November 2026 Patch Tuesday gbhackers.com
- Strix: CVE-2026-110066 (third-party, 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 11 Nov 2026, 12:33.
Original description (NVD)
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information 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.