Answer in brief
CVE-2026-84379 records a Medium severity (CVSS 5.3) vulnerability in HTTPX2: Multipart part header injection via unvalidated file Content-Type and custom headers. The current sources do not mark it as known exploited. The current feed maps pydantic/httpx2 (generic), httpx2 (pip), httpx2 (pypi). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps pydantic/httpx2 (generic), httpx2 (pip), httpx2 (pypi). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| pydantic/httpx2generic | < 2.11.0 | Not reported |
| httpx2pip | <2.11.0 | 2.11.0 |
| httpx2pypi | >=0 <2.11.0 | 2.11.0 |
Published upstream
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 2, 2026
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.
Quoted source text, attributed separately from HOL analysis.