Microsoft Office Excel: Untrusted pointer dereference allows local code execution
Summary
Microsoft Office Excel contains an untrusted pointer dereference (CWE-822) that allows an unauthorized attacker to execute code. The CVSS vector is local (AV:L) with user interaction (UI:R), so the realistic path is a user opening a malicious spreadsheet from an email, download or shared file. Successful exploitation would give the attacker full control over confidentiality, integrity and availability on the affected system. The CNA title mentions Remote Code Execution, but the description and vector indicate a local attack, so the MSRC advisory should be checked.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 before the fix (see MSRC for exact build)
- Office 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 (unverified, from aggregator)
- Office LTSC for Mac 2021 and 2024: before 16.115.26110837 (unverified, from aggregator)
- Office Online Server: 16.0.0.0 before 16.0.10417.20236 (unverified, from aggregator)
Fixed in
- Microsoft 365 Apps for Enterprise: update via https://aka.ms/OfficeSecurityReleases (November 2026 security update)
- Office for Mac and LTSC for Mac: 16.115.26110837 or later (aggregator data, verify on MSRC)
- Office LTSC 2021: 16.0.14334.21048 or later
- Office LTSC 2024: 16.0.17932.21140 or later (unverified)
- Office Online Server: 16.0.10417.20236 or later (unverified)
Workaround
Unknown. No vendor workaround was identified. Patching is the remedy.
Exploitation
No known exploitation and no public proof-of-concept as of the review date. CISA SSVC: exploitation none, automatable no, technical impact total.
Our recommendation
- Install the November 2026 Office security updates on all Office installations (Click-to-Run, Mac, LTSC), starting with Microsoft 365 Apps.
- Verify installed build numbers against the MSRC fixed-build table, not only aggregator data.
- Keep macro restrictions and attachment blocking enabled and keep Protected View active.
- Monitor the MSRC entry for changes in exploitation status.
- Prioritise the whole November Excel batch, as it contains several critical Office RCE flaws.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Remote code execution – Microsoft Office Excel
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Microsoft Office
- Updates (KB)
- KB5002946
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-118723 msrc.microsoft.com
- CVE Record CVE-2026-118723 (CVE.org) www.cve.org
- Strix: CVE-2026-118723 www.strix.ai
- CVE-2026-118723 aggregator entry (threatint) cve.threatint.com
- VulDB entry for Office Excel product classification vuldb.com
- Action1: Patch Tuesday November 2026 www.action1.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 11 Nov 2026, 03:55.
Original description (NVD)
Untrusted pointer dereference in Microsoft Office Excel 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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