๐Ÿ” CVE Alert

CVE-2026-84379

MEDIUM 5.3

HTTPX2: Multipart part header injection via unvalidated file Content-Type and custom headers

CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-93
Vendor pydantic
Product httpx2
Published Sep 2, 2026
Last Updated Sep 2, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

Affected Versions

pydantic / httpx2
< 2.11.0

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/pydantic/httpx2/security/advisories/GHSA-h4x7-gw46-3wm6 github.com: https://github.com/pydantic/httpx2/pull/1142 github.com: https://github.com/pydantic/httpx2/commit/de96d810ee4e309d118982fe7084a46a2bcd600d github.com: https://github.com/pydantic/httpx2/releases/tag/v2.11.0