CVE-2023-38182

Authenticated code execution via undisclosed deserialization

Published Aug 8, 2023 · Updated Aug 10, 2026

Deserialization of untrusted data in Microsoft Exchange Server allows remote authenticated users on the local network to execute code. Microsoft has not disclosed the deserializing component or object-processing operation that accepts attacker-controlled data. Exploitation requires valid Exchange credentials and local-network access and yields code execution through a PowerShell remoting session with SYSTEM privileges.

CVSS severity8.0
High
EPSS probability5.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization of untrusted data in Microsoft Exchange Server allows remote authenticated users on the local network to execute code. Microsoft has not disclosed the deserializing component or object-processing operation that accepts attacker-controlled data. Exploitation requires valid Exchange credentials and local-network access and yields code execution through a PowerShell remoting session with SYSTEM privileges.

The record

CVE
CVE-2023-38182
Published
Aug 8, 2023
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Microsoft Exchange Server 2019 Cumulative Update 12
Classifications
CWE-502, T1059.001
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 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=15.02.0 <15.02.1118.037

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft Exchange Server 2019 Cumulative Update 12version=15.02.0 <15.02.1118.037
Microsoft · Microsoft Exchange Server 2019 Cumulative Update 13version=15.02.0 <15.02.1258.025
Microsoft · Microsoft Exchange Server 2016 Cumulative Update 23version=15.01.0 <15.01.2507.032

Published CVSS scores

8.0Microsoft CorporationCVSS:3.1/AV:A/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1059.001PowerShell

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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