CVE-2026-84380
Publication date 3 September 2026
Last updated 4 September 2026
Ubuntu priority
Description
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| python-httpx2 | 26.04 LTS resolute | Not in release |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release |
Severity score breakdown
CVSS version: CVSS v3.0
Base score
5.6 · Medium
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-84380
- https://github.com/pydantic/httpx2/security/advisories/GHSA-pf96-p4fj-6566
- https://github.com/pydantic/httpx2/pull/1137
- https://github.com/pydantic/httpx2/commit/829b93a2393212996f613e635261f777d9ec6eab
- https://github.com/pydantic/httpx2/releases/tag/v2.11.0