CVE-2023-36435Network attack vector

Service interruption via repeated transport-parameter decoding

Published Oct 10, 2023 · Updated Apr 14, 2025

Memory exhaustion in Microsoft QUIC in affected .NET 7.0, PowerShell 7.3, and Windows releases allows remote attackers to interrupt services. QuicCryptoTlsReadExtensions accepts repeated QUIC transport-parameter TLS extensions, and decoding overwrites VersionInfo without releasing the prior allocation. An unauthenticated network peer can repeat this input until the MsQuic server exhausts memory, interrupting the hosting process or service.

CVSS severity7.5
High
EPSS probability5.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory exhaustion in Microsoft QUIC in affected .NET 7.0, PowerShell 7.3, and Windows releases allows remote attackers to interrupt services. QuicCryptoTlsReadExtensions accepts repeated QUIC transport-parameter TLS extensions, and decoding overwrites VersionInfo without releasing the prior allocation. An unauthenticated network peer can repeat this input until the MsQuic server exhausts memory, interrupting the hosting process or service.

The record

CVE
CVE-2023-36435
Published
Oct 10, 2023
Updated
Apr 14, 2025
Vendor
Microsoft
Product
PowerShell 7.3
Classifications
CWE-401, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 14, 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=7.3.0 <7.3.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · PowerShell 7.3version=7.3.0 <7.3.9
Microsoft · Windows 11 version 21H2version=10.0.0 <10.0.22000.2538
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.2428
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.2031
Microsoft · .NET 7.0version=7.0.0 <7.0.13

Published CVSS scores

7.5MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

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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