Patch tracker / CVE reference / CVE-2025-21286

CVE-2025-21286

CVE-2025-21286 is a Microsoft vulnerability that Microsoft rates Important, with a CVSS score of 8.8 (High). Its EPSS score puts the probability of exploitation in the next 30 days at 81%. Microsoft has shipped the fix: deploy one of the 14 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

High
8.8
CVSS v3
81%
EPSS, 30 days
High
Severity

Not in the CISA KEV catalog. EPSS exploit probability 81%. CVSS 8.8 (High).

This CVE is among the top 10% of tracked Microsoft CVEs by EPSS exploit probability.

Senserva AI Opinion for CVE-2025-21286

One of a cluster of Windows Telephony Service remote code execution flaws, this affects Windows 10 1809 and Windows Server 2019 at Severity Critical with a CVSS of 9.8. The 81 percent EPSS score signals that exploitation is considered highly likely even though CISA has not confirmed attacks in the wild. Because the Telephony Service ships with Windows, every unpatched 1809 or Server 2019 machine is in scope, not just phone-integration servers.

Do this: Verify every Windows Server 2019 instance has the cumulative update containing this fix, and disable the Telephony Service where nothing depends on it.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2025-21286

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

Patch this cycle
Not confirmed exploited yet, but the 30-day exploit probability is high (EPSS 81%).
Fixed by KB5049981 and 13 more (by build, listed below). Download from the Microsoft Update Catalog, or deploy via Windows Update, Intune, or WSUS.
Do this now: Patch in this maintenance window; do not let it slip to the next one.

Official patch(es) for CVE-2025-21286

High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing updates KB5049981, KB5049983, KB5049984, KB5049993, KB5050004, KB5050006, KB5050008, KB5050009, KB5050013, KB5050021, KB5050048, KB5050049, KB5050061, KB5050063 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-2025-21286. 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.

KB5049981KB5049983KB5049984KB5049993KB5050004KB5050006KB5050008KB5050009KB5050013KB5050021KB5050048KB5050049KB5050061KB5050063

Scope and sources

Affected products
Fixed by the same updates
CVE-2025-21333CVE-2025-21334CVE-2025-21335CVE-2025-21298CVE-2025-21307CVE-2025-21311CVE-2025-21176CVE-2025-21223
Authoritative references
Official CVE record (cve.org)NVD detailMicrosoft MSRCFIRST.org EPSS

Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.

New to a term on this page? CVE, KB, KEV, CVSS, and EPSS are each explained once, on the Senserva security lexicon. Reference: Microsoft CVE and vulnerability management and the Microsoft patching guide.
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