CVE-2026-84379

MEDIUM CVSS 3.1: 5.3 EPSS 0.26%
Updated Sep 10, 2026
Python
Parameter Value
CVSS 5.3 (MEDIUM)
Fixed In 2.11.0
Type CWE-93
Vendor Python
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
Low
Partial data modification
Availability
None
No disruption

CVSS Vector v3.1

Weakness Type (CWE)