Is CVE-2026-105591 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-105591 being exploited in the wild.

How severe is CVE-2026-105591?

High severity, with a CVSS score of 8.8, published 13 October 2026.

Is there a fix for CVE-2026-105591?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-105591 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-105591?

Check whether you run Microsoft 365 Apps, Microsoft Office 2021, Microsoft Office 2024 or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-105591: Microsoft Office Access heap-based buffer overflow

CVE-2026-105591 · Severity: high · CVSS 8.8 · Published 2026-10-13

Microsoft Office Access, a database management application widely used for business data storage and reporting, contains a heap-based buffer overflow vulnerability that allows an attacker to execute arbitrary code remotely. An attacker can exploit this flaw by sending a specially crafted file or network request, potentially gaining full control of the affected system and accessing sensitive business data.

Technologies: Microsoft 365 Apps, Microsoft Office 2021, Microsoft Office 2024, Microsoft Office Access. Vendors: Microsoft.

Quick answers

Is CVE-2026-105591 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-105591 being exploited in the wild.
How severe is CVE-2026-105591?: High severity, with a CVSS score of 8.8, published 13 October 2026.
Which products and versions are affected?: Microsoft Office Access.
Is there a fix for CVE-2026-105591?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-105591 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-105591?: Check whether you run Microsoft 365 Apps, Microsoft Office 2021, Microsoft Office 2024 or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap-based buffer overflow exists in Microsoft Office Access that can be triggered over the network without authentication. The vulnerability allows remote code execution when a user opens a specially crafted file. There is no indication of a public exploit in the wild at this time.

Affected products

Microsoft Office Access

Timeline

2026-10-13: disclosed

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-105591

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