Patch tracker / CVE reference / CVE-2026-118153
CVE-2026-118153
CVE-2026-118153 is a Microsoft vulnerability that Microsoft rates Important, with a CVSS score of 7.5 (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.
Our data comes from Microsoft, CISA and other public sources, and it can be wrong or out of date. If you are unsure, check the linked source before you act, and tell us when we are wrong so we can fix it.
Microsoft rates it Important. CVSS 7.5 (High). Fixed by 1 Microsoft security update.
Risk summary
Not in the CISA KEV catalog. EPSS exploit probability Not scored. CVSS 7.5 (High).
CVE-2026-118153 is a denial of service flaw in Microsoft Exchange Server Subscription Edition RTM, rated Severity High with a CVSS score of 8.8. Only organizations running on-premises Exchange Subscription Edition at the RTM build are exposed, and a successful attack would threaten mail flow availability rather than data confidentiality. It is not listed in CISA KEV and has no known ransomware use, so the risk right now is a high-scoring but unconfirmed-exploitation issue on a mail server that is often internet-facing.
Do this: Check whether your Exchange Subscription Edition servers are still on the RTM build and apply the Microsoft security update for CVE-2026-118153 as soon as it clears your test window, prioritizing any servers reachable from the internet.
AI-generated from public data, 2026-11-10. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-118153
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Official patch(es) for CVE-2026-118153
Moderate priority: schedule it in your normal patch cycle. In Intune or Defender, confirm whether the fixing update KB5133453 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-2026-118153. 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
- 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.