Microsoft Office LTSC for Mac 2021 vulnerabilities

5 known vulnerabilities in Microsoft Office LTSC for Mac 2021 from Microsoft. 5 are rated high or critical, and 2 have been exploited in real attacks. Each entry lists the affected versions and the release that fixes it, where the vendor has published one.

Latest first

• 8.8 High severity

  Microsoft 365 Apps for Enterprise: Access of Resource Using Incompatible Type

  CVE-2026-65807Aug 11, 2026Microsoft

  Access of resource using incompatible type ('type confusion') in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.

• 7.0 High severity

  Microsoft 365 Apps for Enterprise: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-44818Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

• 7.8 High severity

  Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision Exploited

  CVE-2026-21514Feb 10, 2026MicrosoftEPSS 1.59%

  Reliance on untrusted inputs in a security decision in Microsoft Office Word allows an unauthorized attacker to bypass a security feature locally.

• 7.8 High severity

  3D Viewer: Heap-based Buffer Overflow

  CVE-2024-20677Jan 9, 2024MicrosoftEPSS 3.26%

  A security vulnerability exists in FBX that could lead to remote code execution. To mitigate this vulnerability, the ability to insert FBX files has been disabled in Word, Excel, PowerPoint and Outlook for Windows and Mac. Versions of Office that had this feat

• 7.8 High severity

  Microsoft Excel Security Feature Bypass Exploited

  CVE-2021-42292Nov 10, 2021MicrosoftEPSS 43%

  Microsoft Excel Security Feature Bypass Vulnerability