Microsoft Office Word: Remote Code Execution via untrusted pointer dereference
Summary
An untrusted pointer dereference in Microsoft Office Word allows an unauthorized attacker to execute code over a network. According to Microsoft, the Reading Pane (Preview Pane) is an attack vector, so a user may not need to open a malicious document. CVSS 9.8 (Critical); Microsoft and CISA SSVC assess automatable exploitation as possible, but no exploitation has been reported.
Affected
- Microsoft 365 Apps for Enterprise (32- and 64-bit): versions from 16.0.1 up to the fixed build; the exact fixed build is unknown, see MSRC
- Microsoft Office LTSC 2021 (32- and 64-bit): versions from 16.0.1 up to but excluding 16.0.14334.20974
- Microsoft Office LTSC 2024 (32- and 64-bit): versions from 16.0.0 up to but excluding 16.0.17932.21056
Fixed in
- Microsoft Office LTSC 2021: 16.0.14334.20974 or later
- Microsoft Office LTSC 2024: 16.0.17932.21056 or later
- Microsoft 365 Apps for Enterprise: Unknown; confirm the fixed build in the Microsoft KB articles linked in the MSRC Security Update Guide
Workaround
- No vendor-confirmed workaround was found in the sources reviewed.
- Our recommendation, not from a source: disable the Preview/Reading Pane in Outlook and File Explorer until patched, where business needs allow. Confirm on the MSRC page that this reduces the attack surface before rolling it out.
Exploitation
- Microsoft: Exploited = No; Exploit Code Maturity = Unproven (no public exploit code known)
- CISA SSVC: exploitation none, automatable yes, technical impact total
- Not listed in the CISA Known Exploited Vulnerabilities catalog at the time of review
- No public proof-of-concept found in our searches; this does not prove that none exists
Our recommendation
- Inventory all Office installations (Microsoft 365 Apps, LTSC 2021 and LTSC 2024) and compare the builds with the MSRC KB articles.
- Install the October 2026 Office security updates first on internet-facing mail and file-sharing systems.
- Disable the Preview/Reading Pane where business needs allow until patched.
- Filter email attachments at the mail gateway and monitor for exploit reports and a CISA KEV addition, as the exploitation status may change.
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 Update Guide: CVE-2026-70300 msrc.microsoft.com
- OpenCVE: CVE-2026-70300 app.opencve.io
- Strix: CVE-2026-70300 www.strix.ai
- Vulners NVD record: CVE-2026-70300 vulners.com
- Rapid7: Patch Tuesday October 2026 www.rapid7.com
- Patchly: Patch Tuesday October 2026 patchly.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 30 Oct 2026, 18:41.
Original description (NVD)
Untrusted pointer dereference in Microsoft Office Word 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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