Microsoft Office Word: Information disclosure due to off-by-one error
Summary
Microsoft Office Word contains an off-by-one error (CWE-193) that allows an unauthenticated attacker to disclose information over the network. The exact data that can be exposed is not described in the public records. Exploitation requires that a user opens a crafted Word document (for example from email or file sharing), and CISA SSVC rates exploitation as none.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the build listed in Microsoft's release notes (exact range unconfirmed)
- Office LTSC 2021: 16.0.1 to before 16.0.14334.21048
- Office LTSC 2024: 16.0.0 to before 16.0.17932.21140 (unconfirmed, see MSRC)
- Office 365 for Mac: 1.0.0 to before 16.115.26110837
- Office LTSC for Mac 2021: 16.0.1 to before 16.115.26110837 (unconfirmed)
- Office LTSC for Mac 2024: 16.0.0 to before 16.115.26110837 (unconfirmed)
Fixed in
- Office 365 for Mac: 16.115.26110837
- Office LTSC 2021: 16.0.14334.21048
- Microsoft 365 Apps for Enterprise: fixed build not stated in the CVE record, see Microsoft's Office security release notes (November 10, 2026)
- Office LTSC 2024, LTSC for Mac 2021 and 2024: fixed builds unconfirmed, see MSRC
Workaround
Unknown. A patch is available, so install the update.
Exploitation
- CISA SSVC: exploitation none, automatable no, technical impact partial
- Rapid7: exploitation less likely, no public disclosure
- Not listed as known exploited (KEV) in the sources reviewed
- No public proof of concept found
Our recommendation
- Install the November 2026 Office security updates on all Microsoft 365, LTSC 2021 and LTSC 2024 clients and on Mac systems, and verify the build numbers against MSRC.
- Keep Protected View enabled for files from the internet and email attachments.
- Filter or sandbox document attachments at the mail gateway.
- Check after updating whether Word documents open without errors.
- Priority: medium.
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-2026-110046 msrc.microsoft.com
- CVE.org record CVE-2026-110046 www.cve.org
- Microsoft Learn: Office security updates learn.microsoft.com
- Rapid7: Patch Tuesday November 2026 www.rapid7.com
- BleepingComputer: Microsoft November 2026 Patch Tuesday www.bleepingcomputer.com
- GBHackers: Microsoft November 2026 Patch Tuesday gbhackers.com
- Strix: CVE-2026-110046 (secondary) 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, 12:34.
Original description (NVD)
Off-by-one error 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.