CVE-2026-45490

Local privilege escalation via weak named-pipe ACL

Published Jun 9, 2026 · Updated Jun 9, 2026

Improper authorization in Microsoft .NET SDK 8.0, 9.0, and 10.0 allows local users to elevate privileges on Windows. The dotnet.exe workload command creates a named pipe with an ACL that lets one local user make the process create or truncate arbitrary files as another local user. Exploitation requires local low-privileged access and an affected SDK workload command; successful use can modify or destroy files with the targeted user's privileges.

CVSS severity7.8
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in Microsoft .NET SDK 8.0, 9.0, and 10.0 allows local users to elevate privileges on Windows. The dotnet.exe workload command creates a named pipe with an ACL that lets one local user make the process create or truncate arbitrary files as another local user. Exploitation requires local low-privileged access and an affected SDK workload command; successful use can modify or destroy files with the targeted user's privileges.

The record

CVE
CVE-2026-45490
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
Microsoft
Product
.NET 9.0
Classifications
CWE-285, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 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=9.0.0 <9.0.17

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · .NET 9.0version=9.0.0 <9.0.17
Microsoft · .NET 10.0version=10.0.0 <10.0.9
Microsoft · .NET 8version=8.0.0 <8.0.28

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-285Improper Authorization
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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