Microsoft Office Word: Information disclosure via buffer over-read
Summary
Microsoft Word, part of Microsoft Office, contains a buffer over-read (CWE-126). An unauthorized attacker can disclose information over a network. Exploitation requires user interaction, and the CVSS vector shows high confidentiality impact only, with no integrity or availability impact. The CVSS 3.1 base score is 6.5 (medium).
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the build listed at https://aka.ms/OfficeSecurityReleases
- Office 365 for Mac: 1.0.0 before 16.115.26110837
- Office LTSC 2021: 16.0.1 before 16.0.14334.21048
- Office LTSC 2024: 16.0.0 before 16.0.17932.21140
- Office LTSC for Mac 2021: 16.0.1 before 16.115.26110837
- Office LTSC for Mac 2024: 16.0.0 before 16.115.26110837
Fixed in
- Microsoft 365 Apps for Enterprise: build number not stated in the CNA record, see https://aka.ms/OfficeSecurityReleases
- Office 365 for Mac and LTSC for Mac: 16.115.26110837 or later
- Office LTSC 2021: 16.0.14334.21048 or later
- Office LTSC 2024: 16.0.17932.21140 or later
Workaround
Unknown.
- No vendor workaround found. Apply the security update.
Exploitation
- Not known to be exploited in the wild. CISA SSVC exploitation status: none.
- Rapid7 rates it 'Exploitation Less Likely'.
- No public proof-of-concept found and no CISA KEV entry found.
Our recommendation
- Install the November 2026 Office security updates on all affected clients, starting with workstations that open external documents.
- Check Microsoft 365, LTSC 2021, LTSC 2024 and Mac installations against the versions listed above.
- Until patched, be cautious with Word documents from untrusted email attachments and downloads.
- Follow the Microsoft Security Update Guide for confirmed fixed builds.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE.org CNA record CVE-2026-124233 www.cve.org
- Microsoft Security Update Guide CVE-2026-124233 msrc.microsoft.com
- Microsoft Office security release notes learn.microsoft.com
- Rapid7 Patch Tuesday November 2026 www.rapid7.com
- Tenable Patch Tuesday November 2026 www.tenable.com
- Strix CVE page CVE-2026-124233 (third-party) 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, 11:58.
Original description (NVD)
Buffer over-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.
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