Microsoft Office Access: Heap-based buffer overflow enables remote code execution
Summary
A heap-based buffer overflow (CWE-122) in Microsoft Office Access allows an unauthenticated attacker to execute code over a network. The attack requires a user to interact with a crafted file or document, such as an opened email attachment or download. Access is an optional component of some Office and Microsoft 365 editions, so exposure depends on whether it is installed.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the fixed build (exact upper bound not confirmed)
- Microsoft Office LTSC 2021: 16.0.1 to below 16.0.14334.20974 (per CNA record)
- Microsoft Office LTSC 2024: 16.0.0 to below 16.0.17932.21056 (per CNA record)
Fixed in
Unknown. The CNA record gives the upper bounds for Office LTSC 2021 (16.0.14334.20974) and Office LTSC 2024 (16.0.17932.21056). The Microsoft 365 Apps threshold could not be confirmed and differs between third-party snapshots. Verify all builds on the MSRC advisory before patching.
Workaround
Unknown. No vendor-documented workaround was found.
Exploitation
- No evidence of exploitation found.
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- EPSS is about 0.7% according to aggregators.
- No public proof of concept found. This does not rule one out.
- CISA KEV status not confirmed; check the catalog directly.
Our recommendation
- Check whether Microsoft Access is installed in your Office and Microsoft 365 environment.
- Apply the Microsoft security update for your channel, using the build thresholds from the MSRC advisory.
- If patching is delayed, block or quarantine .accdb and .mdb files at the mail gateway and on file shares unless business-required.
- Use Office file-block policies to restrict Access files from the internet and email.
- Train staff to be cautious with unexpected database attachments.
- Monitor for exploitation and check the CISA KEV catalog regularly.
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-2026-105716 msrc.microsoft.com
- Vulners mscve record CVE-2026-105716 vulners.com
- Strix CVE record CVE-2026-105716 www.strix.ai
- GitHub CVE issue 1853 (exploitation status) github.com
- Vulners Rapid7 record (EPSS) vulners.com
- CISA Known Exploited Vulnerabilities Catalog www.cisa.gov
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 31 Oct 2026, 19:14.
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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