Microsoft Office Access: Remote code execution via heap-based buffer overflow
Summary
A heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code over a network. The attack requires that a user interacts with the crafted file, which is most likely delivered by phishing or an untrusted download. The CVSS base score is 8.8 (High). Access is only installed when selected, so not every Office installation is affected.
Affected
- Microsoft 365 Apps for Enterprise (32-bit and x64): from 16.0.1 before the fix listed on https://aka.ms/OfficeSecurityReleases
- Office LTSC 2021 (32-bit and x64): from 16.0.1 before 16.0.14334.21048
- Office LTSC 2024 (32-bit and x64): from 16.0.0 before 16.0.17932.21140
Fixed in
- Office LTSC 2021: 16.0.14334.21048 or later
- Office LTSC 2024: 16.0.17932.21140 or later
- Microsoft 365 Apps for Enterprise: Unknown. Fixed build not confirmed; check the current build on the Microsoft release page and the MSRC advisory. The fix is part of the November 2026 Patch Tuesday update.
Workaround
- No vendor workaround known.
- Until patched, block or quarantine Access files (.accdb, .mdb) from email and untrusted downloads.
- Keep Protected View enabled.
Exploitation
- Exploit Code Maturity is Unproven (E:U) at publication.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
- Not listed in CISA KEV at the time of research.
- No public proof of concept found and no evidence of in-the-wild exploitation.
Our recommendation
- Patch Microsoft 365 Apps and Office LTSC installations with the November 2026 updates, via Microsoft 365, WSUS or Intune.
- Verify the installed build on each system against the fixed versions above.
- Prioritise users who regularly open database files from external sources.
- Block or quarantine Access files from untrusted sources until patched.
- Monitor for unusual Office process activity after opening files.
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 (MSRC advisory) msrc.microsoft.com
- CVE.org record CVE-2026-110059 www.cve.org
- Strix CVE-2026-110059 www.strix.ai
- BleepingComputer: November 2026 Patch Tuesday www.bleepingcomputer.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 10 Nov 2026, 23:44.
Original description (NVD)
Heap-based buffer overflow in Microsoft Office Access 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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