CVE-2025-57804

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Source
https://nvd.nist.gov/vuln/detail/CVE-2025-57804
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-57804.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-57804
Aliases
Downstream
Published
2025-08-25T21:15:37Z
Modified
2025-08-26T21:07:23.945073Z
Summary
[none]
Details

h2 is a pure-Python implementation of a HTTP/2 protocol stack. Prior to version 4.3.0, an HTTP/2 request splitting vulnerability allows attackers to perform request smuggling attacks by injecting CRLF characters into headers. This occurs when servers downgrade HTTP/2 requests to HTTP/1.1 without properly validating header names/values, enabling attackers to manipulate request boundaries and bypass security controls. This issue has been patched in version 4.3.0.

References

Affected packages

Debian:11 / python-h2

Package

Name
python-h2
Purl
pkg:deb/debian/python-h2?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.0.0-3
4.1.0-1
4.1.0-2
4.1.0-3
4.1.0-4
4.2.0-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:12 / python-h2

Package

Name
python-h2
Purl
pkg:deb/debian/python-h2?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.1.0-4
4.2.0-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:13 / python-h2

Package

Name
python-h2
Purl
pkg:deb/debian/python-h2?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.2.0-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:14 / python-h2

Package

Name
python-h2
Purl
pkg:deb/debian/python-h2?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.2.0-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Git / github.com/python-hyper/h2

Affected ranges

Type
GIT
Repo
https://github.com/python-hyper/h2
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
035e9899f95e3709af098f578bfc3cd302298e3a

Affected versions

v1.*

v1.0.0
v1.1.0
v1.1.1

v2.*

v2.0.0
v2.1.0
v2.2.0
v2.3.0
v2.4.0
v2.5.0
v2.6.0

v3.*

v3.0.0
v3.1.0
v3.1.1
v3.2.0

v4.*

v4.0.0
v4.1.0
v4.2.0