CVE-2023-38171
Microsoft QUIC Denial of Service Vulnerability
Microsoft QUIC Denial of Service Vulnerability
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Microsoft QUIC Denial of Service Vulnerability
Microsoft QUIC Denial of Service Vulnerability
- Record
CVE-2023-38171- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C - Weakness
- CWE-476
- Updated
- 2026-11-02
EUVDEUVD-2023-2837
Microsoft QUIC Denial of Service Vulnerability
- Record
EUVD-2023-2837- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-xh5m-8qqp-c5x7
Remote Denial of Service Vulnerability in Microsoft.Native.Quic.MsQuic.Schannel
Impact
The MsQuic server application or process will crash, resulting in a denial of service.
Patches
The following patch was made:
- Don't Allow Version Negotiation Packets for Server Connections - https://github.com/microsoft/msquic/commit/3226cff07d22662f16fc98d605656860e64cd343
Workarounds
Beyond upgrading to the patched versions, there is no other workaround. You must upgrade or disable MsQuic functionality.
- Record
GHSA-xh5m-8qqp-c5x7- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-476
- Updated
- 2026-11-02
NVD
Microsoft QUIC Denial of Service Vulnerability
- Record
CVE-2023-38171- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-476
- Updated
- 2026-11-02
OSVALPINE-CVE-2023-38171
Microsoft QUIC Denial of Service Vulnerability
- Record
ALPINE-CVE-2023-38171- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
OSV
Microsoft QUIC Denial of Service Vulnerability
- Record
CVE-2023-38171- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVGHSA-xh5m-8qqp-c5x7
Remote Denial of Service Vulnerability in Microsoft.Native.Quic.MsQuic.Schannel
Impact
The MsQuic server application or process will crash, resulting in a denial of service.
Patches
The following patch was made:
- Don't Allow Version Negotiation Packets for Server Connections - https://github.com/microsoft/msquic/commit/3226cff07d22662f16fc98d605656860e64cd343
Workarounds
Beyond upgrading to the patched versions, there is no other workaround. You must upgrade or disable MsQuic functionality.
- Record
GHSA-xh5m-8qqp-c5x7- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-476
- Updated
- 2026-11-02
OSVBIT-dotnet-2023-38171 No score
Microsoft QUIC Denial of Service Vulnerability
Microsoft QUIC Denial of Service Vulnerability
- Record
BIT-dotnet-2023-38171- Updated
- 2026-11-02
OSVBIT-dotnet-sdk-2023-38171 No score
Microsoft QUIC Denial of Service Vulnerability
Microsoft QUIC Denial of Service Vulnerability
- Record
BIT-dotnet-sdk-2023-38171- Updated
- 2026-11-02
Affected products
- microsoft .net
- microsoft .net 7.0
- microsoft visual studio 2022 version 17.2
- microsoft visual studio 2022 version 17.4
- microsoft visual studio 2022 version 17.6
- microsoft visual studio 2022 version 17.7
- microsoft powershell 7.3
- microsoft visual studio 2022
- microsoft windows 11 version 21h2
- microsoft windows 11 version 22h2
- microsoft windows server 2022
- microsoft windows 11 22h2
Affected packages
| Package | Affected | Fixed |
|---|---|---|
Microsoft.Native.Quic.MsQuic.SchannelNuGet |
before 2.2.3 | 2.2.3 |
Microsoft.Native.Quic.MsQuic.OpenSSLNuGet |
before 2.2.3 | 2.2.3 |
dotnet7-buildAlpine:v3.18 |
before 7.0.112-r0 | 7.0.112-r07.0.113-r0 |
dotnet7-buildAlpine:v3.19 |
before 7.0.112-r0 | 7.0.112-r07.0.113-r0 |
dotnet7-runtimeAlpine:v3.18 |
before 7.0.12-r0 | 7.0.12-r07.0.13-r0 |
dotnet7-runtimeAlpine:v3.19 |
before 7.0.12-r0 | 7.0.12-r07.0.13-r0 |
dotnetBitnami |
7.0.0 up to 7.0.12 | 7.0.12 |
dotnet-sdkBitnami |
7.0.0 up to 7.0.12 | 7.0.12 |
Microsoft.Native.Quic.MsQuic.SchannelNuGet |
before 2.2.3, plus listed versions 1.8.0 |
2.2.3 |
Microsoft.Native.Quic.MsQuic.OpenSSLNuGet |
before 2.2.3, plus listed versions 1.8.0 |
2.2.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-38171 is a high vulnerability (CVSS 7.5) in Microsoft .net, published October 10, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 71.0%, the 99th percentile. Fixed in Microsoft.Native.Quic.MsQuic.Schannel 2.2.3.
References
msrc.microsoft.com/update-guide/vulnerability/CVE-2023-38171
github.com/microsoft/msquic/security/advisories/GHSA-xh5m-8qqp-c5x7
nvd.nist.gov/vuln/detail/CVE-2023-38171
security.alpinelinux.org/vuln/CVE-2023-38171