CVE-2026-3006

Local SYSTEM access via kernel heap overflow

Published Apr 27, 2026 · Updated Apr 27, 2026

Race condition in WinFsp 2.1.25156 and earlier allows local users to gain SYSTEM access by triggering a kernel heap overflow. Neither CSA nor the upstream release discloses the affected driver routine, shared resource, or unsynchronized operation that corrupts the heap. Exploitation requires low-privileged local access and successful race timing; SYSTEM access permits full host compromise.

CVSS severity7.0
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in WinFsp 2.1.25156 and earlier allows local users to gain SYSTEM access by triggering a kernel heap overflow. Neither CSA nor the upstream release discloses the affected driver routine, shared resource, or unsynchronized operation that corrupts the heap. Exploitation requires low-privileged local access and successful race timing; SYSTEM access permits full host compromise.

The record

CVE
CVE-2026-3006
Published
Apr 27, 2026
Updated
Apr 27, 2026
Vendor
WinFsp
Product
WinFsp
Classifications
CWE-362, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.1.25156 and lower

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

WinFsp · WinFspversion=2.1.25156 and lower

Published CVSS scores

7.0Cyber Security Agency of SingaporeCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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