Patch tracker / CVE reference / CVE-2025-21197
CVE-2025-21197
CVE-2025-21197 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 13%. 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.
High severity Microsoft vulnerability, CVSS 8.8. Fixed by 14 Microsoft security updates.
Risk summary
Updated July 24, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Senserva AI Opinion for CVE-2025-21197
This information disclosure flaw is in NTFS itself, the core Windows file system, rather than a network facing service like RRAS, so exposure exists on essentially every Windows 10 1809 and Server 2019 machine with local storage. An 18 percent EPSS score keeps it at moderate priority, similar to the RRAS cluster nearby in this list.
Do this: Patch this as part of standard OS updates. Unlike the RRAS bugs, there is no service to disable here since NTFS is fundamental to the file system.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2025-21197
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2025-21197
Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.
Exploitation and severity
Not in the CISA KEV catalog. EPSS exploit probability 13%. CVSS 8.8 (High).
This CVE is among the lower half of tracked Microsoft CVEs by EPSS exploit probability.
Official patch(es) for CVE-2025-21197
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 KB5055518, KB5055519, KB5055521, KB5055523, KB5055526, KB5055527, KB5055528, KB5055547, KB5055557, KB5055561, KB5055570, KB5055581, KB5055596, KB5055609 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-2025-21197. 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.
Affected products
Common questions about CVE-2025-21197
Is CVE-2025-21197 actively exploited?
It is not currently listed in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score puts the probability of exploitation in the next 30 days at 13%.
What patch fixes CVE-2025-21197?
Microsoft fixed CVE-2025-21197 in KB5055518, KB5055519, KB5055521, KB5055523, KB5055526, KB5055527, KB5055528, KB5055547, KB5055557, KB5055561, KB5055570, KB5055581, KB5055596, KB5055609. Download from the Microsoft Update Catalog, or let Intune, Windows Update, or WSUS deliver it.
Which products are affected by CVE-2025-21197?
Windows 10 Version 1809 for 32-bit Systems, Windows 10 Version 1809 for x64-based Systems, Windows Server 2019.
Can I ask my own AI about CVE-2025-21197?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2025-21197's key facts: severity, CVSS, EPSS exploit probability, CISA KEV status, and the fixing KB. Copy it into Claude, ChatGPT, or Copilot for a triage plan; the data is refreshed three times a day (5 AM, 12:30 PM, and 7 PM US Central).
Fixed by the same updates
If you are patching CVE-2025-21197, the same updates also fix these:
Authoritative references
Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.
