Archer Special Advisory: Microsoft Office Vulnerability (CVE-2026-21509)

Archer Special Advisory: Microsoft Office Vulnerability (CVE-2026-21509)

Special advisories relate to CVEs and security events with broad industry interest even when we know our products and platforms are not affected.

Applies To

 Microsoft Office Zero-Day Publication: CVE-2026-21509 - Security Update Guide - Microsoft - Microsoft Office Security Feature Bypass Vulnerability

CVE Details: NVD - CVE-2026-21509

Details

 Archer is aware of the Microsoft Office Zero Day CVE 2026 21509 that was disclosed on January 27, 2026.

A small number of clients have shared that they are encountering issues when exporting files from the Archer Platform in both SaaS and OnPrem environments. In some cases, the exported files appear to be corrupt when opened in Excel. These issues may occur after a patch for this vulnerability has been applied to a local Windows operating system.

We encourage clients to follow Microsoft guidance related to this event and to contact Microsoft directly for support with any issues that arise after applying the patch.

Archer will continue to monitor the situation and share updates as needed.

Legal Information

Read and use the information in this Archer Security Advisory to assist in avoiding any situation that might arise from the problems described herein. If you have any questions regarding this advisory, contact Archer Technical Support. Archer distributes Archer Security Advisories in order to bring to the attention of users of the affected Archer products important security information.

Originally posted on January 29, 2026 in the Archer Community.