# CVE-2026-84379: python-httpx2: HTTPX2 is a next generation HTTP client for Python

CVE-2026-84379 is fixed in python-httpx2 on 1 platform by DEBIAN-CVE-2026-84379 (version 2.12.0-1), released September 8, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-84379
- Priority: Routine
- CVSS: 5.3 (medium)
- EPSS: 0.0032
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 2, 2026

## Description

HTTPX2 is a next generation HTTP client for Python. Prior to 2.11.0, FileField.render_headers() in src/httpx2/httpx2/_multipart.py directly interpolates attacker-controlled content_type values and custom headers from the files= three-element (filename, content, content_type) tuple and the files= four-element (filename, content, content_type, headers) tuple into multipart/form-data part headers without validating header names or values. CR or LF characters can terminate a part header, inject additional part headers, or end the part header block early, allowing a downstream multipart parser to treat attacker-supplied lines as genuine headers and potentially alter part semantics or bypass header-based checks. This issue is fixed in version 2.11.0.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-httpx2 Debian 14 | 2.12.0-1 | [DEBIAN-CVE-2026-84379](https://patchblox.com/security/data/fix/linux/debian-cve-2026-84379.md) | Sep 8, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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