CVE-2026-84379
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=…
Does this matter?
Lower severity and a low EPSS score (0.26%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.26% probability · 18th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-93
- Source
- security-advisories@github.com
References
- https://github.com/pydantic/httpx2/commit/de96d810ee4e309d118982fe7084a46a2bcd600d
- https://github.com/pydantic/httpx2/pull/1142
- https://github.com/pydantic/httpx2/releases/tag/v2.11.0
- https://github.com/pydantic/httpx2/security/advisories/GHSA-h4x7-gw46-3wm6
- https://github.com/pydantic/httpx2/security/advisories/GHSA-h4x7-gw46-3wm6
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.