CVE-2023-23392Network attack vector

Unauthenticated code execution via HTTP/3 use-after-free

Published Mar 14, 2023 · Updated Jan 1, 2025

Use-after-free in Microsoft Windows 11 and Windows Server 2022 HTTP/3 processing allows remote attackers to execute arbitrary code. Microsoft identifies HTTP.sys HTTP/3 processing as the affected locus but has not disclosed the exact lifetime error or affected routine. Exploitation requires an HTTP/3-enabled binding that uses buffered I/O and succeeds without authentication or user interaction.

CVSS severity9.8
Critical
EPSS probability1.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Microsoft Windows 11 and Windows Server 2022 HTTP/3 processing allows remote attackers to execute arbitrary code. Microsoft identifies HTTP.sys HTTP/3 processing as the affected locus but has not disclosed the exact lifetime error or affected routine. Exploitation requires an HTTP/3-enabled binding that uses buffered I/O and succeeds without authentication or user interaction.

The record

CVE
CVE-2023-23392
Published
Mar 14, 2023
Updated
Jan 1, 2025
Vendor
Microsoft
Product
Windows 11 version 21H2
Classifications
CWE-416, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 1, 2025Record 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=10.0.0 <10.0.22000.1696

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Windows 11 version 21H2version=10.0.0 <10.0.22000.1696
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.1413
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.1607

Published CVSS scores

8.5MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
9.8MicrosoftCVSS:3.1/AV:N/AC:L/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1190Exploit Public-Facing Application

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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