CVE-2026-21509 | Microsoft Office/365 Apps for Enterprise/Office LTSC reliance on untrusted inputs in a security decision

A vulnerability has been found in Microsoft Office, 365 Apps for Enterprise and Office LTSC and classified as critical. The impacted element is an unknown function. This manipulation causes reliance on untrusted inputs in a security decision.

This vulnerability is tracked as CVE-2026-21509. The attack is possible to be carried out remotely. No exploit exists.