CVE-2026-84380

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Source
https://cve.org/CVERecord?id=CVE-2026-84380
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84380.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-84380
Aliases
  • GHSA-pf96-p4fj-6566
Downstream
Published
2026-09-02T17:58:55Z
Modified
2026-09-04T03:47:27Z
Severity
  • 5.6 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L CVSS Calculator
Summary
HTTPX2: Conflicting Content-Length and Transfer-Encoding headers can be auto-generated
Details

HTTPX2 is a next generation HTTP client for Python. Prior to 2.11.0, Request._prepare() in src/httpx2/httpx2/_models.py can add a body-derived Content-Length header to a request that already contains a caller-supplied Transfer-Encoding header because its setdefault() processing checks each default header independently rather than treating the two framing headers as mutually exclusive. Fixed-size byte, JSON, form, and known-length multipart bodies can therefore be serialized over HTTP/1.1 with both headers, allowing request smuggling or connection desynchronization when downstream intermediaries disagree about which framing header takes precedence. This issue is fixed in version 2.11.0.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-444"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84380.json"
}
References

Affected packages

Git / github.com/pydantic/httpx2

Affected ranges

Type
GIT
Repo
https://github.com/pydantic/httpx2
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
829b93a2393212996f613e635261f777d9ec6eab
Fixed
2b13fa92e4181d5e0f56772205360b2aa12f109d
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.11.0"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

v2.*
v2.0.0
v2.0.0b1
v2.1.0
v2.10.0
v2.2.0
v2.3.0
v2.4.0
v2.5.0
v2.6.0
v2.7.0
v2.8.0
v2.9.0
v2.9.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84380.json"