Microsoft Office Word: Heap-based buffer overflow leading to code execution
Summary
A heap-based buffer overflow in Microsoft Office Word allows code execution on the affected computer. According to the CVE record, the attack is local and requires a user to open a crafted document, for example one received by email or from a file share. Microsoft rates the flaw as Important, and CISA SSVC reports total technical impact but no known exploitation.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the fixed build
- Office 365 for Mac: versions before 16.114.26101123
- Office LTSC 2021: versions before 16.0.14334.20974 (unverified)
- Office LTSC 2024: versions before 16.0.17932.21056 (unverified)
- Office LTSC for Mac 2021 and 2024: versions before 16.114.26101123
Fixed in
- Microsoft 365 Apps for Enterprise: Unknown, build not confirmed. Check Microsoft release notes.
- Office 365 for Mac: 16.114.26101123 (per CNA data)
- Office LTSC 2021: 16.0.14334.20974 (unverified)
- Office LTSC 2024: 16.0.17932.21056 (unverified)
- Office LTSC for Mac 2021 and 2024: Unknown
- Microsoft lists CVE-2026-97001 in the 13 Oct 2026 Office security updates.
Workaround
Unknown. No workaround or mitigation is documented in the sources. Installing the update is the fix.
- General hardening, not a fix: Protected View and Mark of the Web limit what downloaded or emailed Office files can do before editing is enabled.
Exploitation
- No evidence of exploitation in the wild found.
- Microsoft CVSS temporal score marks exploit code maturity as Unproven (E:U).
- CISA SSVC: exploitation none, automatable no, technical impact total.
- Not listed in CISA KEV. No public proof of concept found.
Our recommendation
- Update all Microsoft Office clients in the October 2026 update cycle, including Mac and LTSC installations.
- Verify the installed build against Microsoft release notes, especially for Microsoft 365 Apps and Mac, where the fixed build is not confirmed in the sources.
- Enable automatic updates for Office.
- Remind staff not to open unexpected or unsolicited Word documents, and keep Protected View enabled.
- Monitor for unusual Office process activity.
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 Response Center: CVE-2026-97001 msrc.microsoft.com
- Microsoft 365 Apps security updates (release notes) learn.microsoft.com
- OpenCVE: CVE-2026-97001 app.opencve.io
- Strix: CVE-2026-97001 (third-party mirror of CNA data) www.strix.ai
- 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 2 Nov 2026, 00:32.
Original description (NVD)
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code locally.
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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