CVE-2025-62456: Windows Resilient File System (ReFS) Remote Code Execution Vulnerability

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-09 · updated 2026-10-07
Weakness: CWE-122

Description

Heap-based buffer overflow in Windows Resilient File System (ReFS) allows an authorized attacker to execute code over a network.

Affected products

Microsoft Windows 11: before 10.0.22631.6345 — fixed in 10.0.22631.6345
Microsoft Windows 11: before 10.0.26100.7392 — fixed in 10.0.26100.7392
Microsoft Windows 11 25H2: before 10.0.26200.7392 — fixed in 10.0.26200.7392
Microsoft Windows Server 2022: before 10.0.20348.4467 — fixed in 10.0.20348.4467
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): before 10.0.25398.2025 — fixed in 10.0.25398.2025
Microsoft Windows Server 2025: before 10.0.26100.7392 — fixed in 10.0.26100.7392
Microsoft Windows 11 version 22H3: from 10.0.22631.0 before 10.0.22631.6345 — fixed in 10.0.22631.6345
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.6345 — fixed in 10.0.22631.6345
Microsoft Windows 11: from 10.0.26100.0 before 10.0.26100.7462 — fixed in 10.0.26100.7462
Microsoft Windows 11 25H2: from 10.0.26200.0 before 10.0.26200.7462 — fixed in 10.0.26200.7462
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.4529 — fixed in 10.0.20348.4529
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): from 10.0.25398.0 before 10.0.25398.2025 — fixed in 10.0.25398.2025
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.7462 — fixed in 10.0.26100.7462

How to fix

Upgrade to a fixed version: Microsoft Windows 11 10.0.22631.6345; Microsoft Windows 11 10.0.26100.7392; Microsoft Windows 11 25H2 10.0.26200.7392; Microsoft Windows Server 2022 10.0.20348.4467; Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.2025; Microsoft Windows Server 2025 10.0.26100.7392; Microsoft Windows 11 version 22H3 10.0.22631.6345; Microsoft Windows 11 10.0.22631.6345; Microsoft Windows 11 10.0.26100.7462; Microsoft Windows 11 25H2 10.0.26200.7462; Microsoft Windows Server 2022 10.0.20348.4529; Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.2025. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-62456

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