CVE-2022-41721
Request smuggling due to improper request handling in golang.org/x/net/http2/h2c
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
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
NVD Score used
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
- Record
CVE-2022-41721- 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-444
- Updated
- 2026-11-02
CVE List
Request smuggling due to improper request handling in golang.org/x/net/http2/h2c
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
- Record
CVE-2022-41721- 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
EUVDEUVD-2023-0462
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
- Record
EUVD-2023-0462- 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
GitHub AdvisoriesGHSA-fxg5-wq6x-vr4w
golang.org/x/net/http2/h2c vulnerable to request smuggling attack
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
Specific Go Packages Affected
golang.org/x/net/http2/h2c
- Record
GHSA-fxg5-wq6x-vr4w- 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-444
- Updated
- 2026-11-02
OSVAZL-13029
CVE-2022-41721 affecting package opa for versions less than 0.50.2-5
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
- Record
AZL-13029- 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
OSV
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
- Record
CVE-2022-41721- 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
Show 4 moreShow less
OSVDEBIAN-CVE-2022-41721
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
- Record
DEBIAN-CVE-2022-41721- 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
OSVGHSA-fxg5-wq6x-vr4w
golang.org/x/net/http2/h2c vulnerable to request smuggling attack
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
Specific Go Packages Affected
golang.org/x/net/http2/h2c
- Record
GHSA-fxg5-wq6x-vr4w- 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-444
- Updated
- 2026-11-02
OSVGO-2023-1495 No score
Request smuggling due to improper request handling in golang.org/x/net/http2/h2c
A request smuggling attack is possible when using MaxBytesHandler.
When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.
- Record
GO-2023-1495- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:12666-1 No score
caddy-2.6.3-1.1 on GA media
These are all security issues fixed in the caddy-2.6.3-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:12666-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
golang.org/x/netGo |
0.0.0-20220524220425-1d687d428aca up to 0.1.1-0.20221104162952-702349b0e862 | 0.1.1-0.20221104162952-702349b0e862 |
opaAzure Linux:2 |
before 0.50.2-5 | 0.50.2-5 |
golang-golang-x-netDebian:12 |
before 1:0.4.0+dfsg-1 | 1:0.4.0+dfsg-1 |
golang-golang-x-netDebian:13 |
before 1:0.4.0+dfsg-1 | 1:0.4.0+dfsg-1 |
golang-golang-x-netDebian:14 |
before 1:0.4.0+dfsg-1 | 1:0.4.0+dfsg-1 |
caddyopenSUSE:Tumbleweed |
before 2.6.3-1.1 | 2.6.3-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2022-41721 is a high vulnerability (CVSS 7.5) in Golang H2c, published January 13, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.82%, the 78th percentile. Fixed in golang.org/x/net 0.1.1-0.20221104162952-702349b0e862.