CVE-2025-29970 — Microsoft Brokering File System Elevation of Privilege Vulnerability

Executive Summary

Use after free in Microsoft Brokering File System allows an authorized attacker to elevate privileges locally.

Overview

7.8

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Elevation of Privilege

Weakness CWE-416: Use After Free

Released May 13 2025

Last Updated May 13 2025

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.00427 — 0.35016 percentile

NVD CVSS 7.8 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 6.8

EPSS Score

0.00427

probability of exploitation in the next 30 days

0.35016 percentile - updated 2026-07-25

View on FIRST.org

Affected Products

1 affected product

Product	KB Article	Severity	Impact	Restart Required
Windows 11 Version 24H2 for ARM64-based Systems 5058411 (Security Update) 5058497 (SecurityHotpatchUpdate) Important Elevation of Privilege 5055523 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.26100.4061 10.0.26100.3981 Yes None Windows 11 Version 24H2 for x64-based Systems 5058411 (Security Update) 5058497 (SecurityHotpatchUpdate) Important Elevation of Privilege 5055523 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.26100.4061 10.0.26100.3981 Yes None Windows Server 2022, 23H2 Edition (Server Core installation)	`5058384 (Security Update)`	Important	Elevation of Privilege	Yes

Patches

1 patch

Article	Type	Restart
`5058384`	Security Update	Yes

Patch Diff

ghidriff · bfs.sys (KB5058411)

Patch diff 10.0.26100.3624 -> 10.0.26100.4061

Pre-patch version 10.0.26100.3624 Download

Post-patch version 10.0.26100.4061 Download

Function	Address	Change	Note
`wil_details_IsEnabledFallback`	`1c0003ff8`	refcount, calling	similarity 1.0
`BfsCloseStorage`	`1c000e23c -> 1c000e320`	code, length, address, called	similarity 0.29
`NTOSKRNL.EXE::ExFreePoolWithTag`	`EXTERNAL:0000007a`	refcount, calling	similarity 1.0

View full diff report View RCA report Download PoC

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Microsoft Offensive Research & Security Engineering
hazard

References

MSRC Advisory MITRE NVD