CVE-2023-33127Public exploit

Cross-session code execution via diagnostic pipe squatting

Published Jul 11, 2023 · Updated May 28, 2026

Improper access control in affected .NET, PowerShell, and Visual Studio releases allows local users to execute code across Windows sessions. The CLR diagnostic server creates a predictable named pipe without requiring the first pipe instance, so a precreated pipe supplies attacker-controlled ownership and permissions. Exploitation requires winning the pipe-creation race and then sending AttachProfiler to load a supplied DLL in the target user's process.

CVSS severity8.1
High
EPSS probability1.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in affected .NET, PowerShell, and Visual Studio releases allows local users to execute code across Windows sessions. The CLR diagnostic server creates a predictable named pipe without requiring the first pipe instance, so a precreated pipe supplies attacker-controlled ownership and permissions. Exploitation requires winning the pipe-creation race and then sending AttachProfiler to load a supplied DLL in the target user's process.

The record

CVE
CVE-2023-33127
Published
Jul 11, 2023
Updated
May 28, 2026
Vendor
Microsoft
Product
.NET 6.0
Classifications
CWE-1220, T1574.012
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 11, 2023CVE publishedPublication date reported by the CVE source.
  2. May 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=6.0.0 <6.0.20

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · .NET 6.0version=6.0.0 <6.0.20
Microsoft · PowerShell 7.3version=7.3.0 <7.3.6
Microsoft · Microsoft Visual Studio 2022 version 17.6version=17.6.0 <17.6.5
Microsoft · Microsoft Visual Studio 2022 version 17.4version=17.4.0 <17.4.9
Microsoft · Microsoft Visual Studio 2022 version 17.0version=17.0.0 <17.0.23
Microsoft · Microsoft Visual Studio 2022 version 17.2version=17.2.0 <17.2.17
Microsoft · .NET 7.0version=7.0.0 <7.0.9
Microsoft · PowerShell 7.2version=7.2.0 <7.2.13

Published CVSS scores

8.1MicrosoftCVSS:3.1/AV:N/AC:H/PR:N/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 exploitPublished

Weakness, pattern, technique

CWE-1220Insufficient Granularity of Access Control
T1574.012COR_PROFILER

Public exploit references

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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