Patch tracker / CVE reference / CVE-2025-21201
CVE-2025-21201
CVE-2025-21201 is a high severity Microsoft vulnerability with a CVSS score of 8.8. Its EPSS score puts the probability of exploitation in the next 30 days at 24%. Microsoft has shipped the fix: deploy one of the 16 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.
Risk summary
Not in the CISA KEV catalog. EPSS exploit probability 24%. CVSS 8.8 (High).
This CVE is among the lower half of tracked Microsoft CVEs by EPSS exploit probability.
CVE-2025-21201 is a remote code execution flaw in the Windows Telephony Server component affecting Windows 10 Version 1809 (32-bit and x64) and Windows Server 2019. At CVSS 8.8 with a 24 percent EPSS exploit probability, it carries meaningful attacker interest even though it is not yet in CISA KEV or tied to ransomware. The 8.8 vector typically implies exploitation over a network with some user or authentication factor, so exposed Telephony services on these older builds are the risk surface.
Do this: Deploy the Microsoft patch for CVE-2025-21201 to all Windows 10 1809 and Windows Server 2019 hosts, prioritizing any systems running the Telephony (TAPI) service.
AI-generated from public data, 2026-07-22. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2025-21201
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Official patch(es) for CVE-2025-21201
Elevated priority: high severity or a meaningful exploitation probability, sooner if an affected product is internet-facing. In Intune or Defender, confirm whether the fixing updates KB5051974, KB5051979, KB5051980, KB5051987, KB5051989, KB5052000, KB5052006, KB5052016, KB5052020, KB5052032, KB5052038, KB5052040, KB5052042, KB5052072, KB5052105, KB5052106 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.
Apply the Microsoft security updates below to fix CVE-2025-21201. 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 updates
- Authoritative references
Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.