Patch tracker / CVE reference / CVE-2026-120789
CVE-2026-120789
CVE-2026-120789 is a Microsoft vulnerability that Microsoft rates Critical, with a CVSS score of 8.8 (High). Microsoft has shipped the fix: deploy the update below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.
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Microsoft rates it Critical. CVSS 8.8 (High). Fixed by 1 Microsoft security update.
Risk summary
Not in the CISA KEV catalog. EPSS exploit probability Not scored. CVSS 8.8 (High).
CVE-2026-120789 is an Excel remote code execution flaw rated High severity (CVSS 8.8) that spans Office Online Server and the LTSC 2021 and 2024 releases of Office for Mac, so exposure covers both a server role and macOS desktops rather than only Windows clients. It is not in CISA KEV and has no known ransomware use, so there is no confirmed exploitation to date. Office Online Server is often internet-reachable for document rendering, which raises the practical risk compared with a desktop-only Excel bug.
Do this: Inventory your Office Online Server hosts and Office LTSC for Mac 2021 and 2024 installs today, and apply Microsoft's patch to the Office Online Server systems first.
AI-generated from public data, 2026-11-10. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-120789
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Official patch(es) for CVE-2026-120789
Moderate priority: schedule it in your normal patch cycle. In Intune or Defender, confirm whether the fixing update KB5002946 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.
Apply the Microsoft security update below to fix CVE-2026-120789. Each KB page carries the Microsoft Update Catalog download, Microsoft's known issues for the update, a copy-paste PowerShell check for whether it is installed, and the Senserva AI read.
Scope and sources
- Affected products
- Microsoft 365 Apps for Enterprise for 32-bit Systems
- Microsoft 365 Apps for Enterprise for 64-bit Systems
- Microsoft Office 365 for Mac
- Microsoft Office LTSC 2021 for 32-bit editions
- Microsoft Office LTSC 2021 for 64-bit editions
- Microsoft Office LTSC 2024 for 32-bit editions
- Microsoft Office LTSC 2024 for 64-bit editions
- Microsoft Office LTSC for Mac 2021
- Microsoft Office LTSC for Mac 2024
- Office Online Server
- Fixed by the same update
- Authoritative references
Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.