Patch tracker / CVE reference / CVE-2026-118712
CVE-2026-118712
CVE-2026-118712 is a Microsoft vulnerability that Microsoft rates Important, 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 Important. 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-2026-118712 is a remote code execution flaw in Microsoft Office Excel, rated Severity High (CVSS 8.8), and it affects Office LTSC 2021 (both 32-bit and 64-bit) and Office LTSC 2024 64-bit. LTSC is the volume-licensed, fixed-feature channel common in locked-down or offline environments, so these installs often patch on a slower cadence than Microsoft 365 Apps. It is not in CISA KEV and has no known ransomware use, so there is no confirmed exploitation to justify emergency handling, but the 8.8 score and Excel's role as a routine email attachment make it a priority for the next patch cycle.
Do this: Inventory your Office LTSC 2021 and LTSC 2024 installs, then deploy Microsoft's fix for CVE-2026-118712 to them, starting with users who regularly open Excel files from outside the organization.
AI-generated from public data, 2026-11-10. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-118712
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Official patch(es) for CVE-2026-118712
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-2026-118712. 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.