GHSA-847f-9342-265h

Suggest an improvement
Source
https://github.com/advisories/GHSA-847f-9342-265h
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/08/GHSA-847f-9342-265h/GHSA-847f-9342-265h.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-847f-9342-265h
Aliases
Related
Published
2025-08-25T20:44:43Z
Modified
2026-02-04T04:12:39.349378Z
Severity
  • 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N CVSS Calculator
Summary
h2 allows HTTP Request Smuggling due to illegal characters in headers
Details

Summary

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.

Database specific 
{
    "github_reviewed": true,
    "nvd_published_at": "2025-08-25T21:15:37Z",
    "cwe_ids": [
        "CWE-93"
    ],
    "github_reviewed_at": "2025-08-25T20:44:43Z",
    "severity": "MODERATE"
}
References

Affected packages

PyPI / h2

Package

Name
h2
View open source insights on deps.dev
Purl
pkg:pypi/h2

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.3.0

Affected versions

0.*
0.1.0
1.*
1.0.0
1.1.0
1.1.1
2.*
2.0.0
2.1.0
2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
2.2.0
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.3.0
2.3.1
2.3.2
2.3.3
2.3.4
2.4.0
2.4.1
2.4.2
2.4.3
2.4.4
2.5.0
2.5.1
2.5.2
2.5.3
2.5.4
2.6.0
2.6.1
2.6.2
3.*
3.0.0
3.0.1
3.1.0
3.1.1
3.2.0
4.*
4.0.0
4.1.0
4.2.0

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/08/GHSA-847f-9342-265h/GHSA-847f-9342-265h.json"