{"cve":"CVE-2026-84379","nvd":{"published":"2026-09-02T18:21:29.300","modified":"2026-09-09T21:05:23.237","status":"Awaiting Analysis","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3},"cwes":["CWE-93"],"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"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:50.842544443+00:00"},"epss":{"cve":"CVE-2026-84379","score":0.00317,"percentile":0.2469,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-h4x7-gw46-3wm6","url":"https://osv.dev/vulnerability/GHSA-h4x7-gw46-3wm6","summary":"HTTPX2: Multipart part header injection via unvalidated file Content-Type and custom headers","modified":"2026-09-10T12:25:35.236610813Z","packages":[{"ecosystem":"PyPI","name":"httpx2","purl":"pkg:pypi/httpx2","ranges":["<2.11.0"],"fixed":["2.11.0"]}]},{"id":"PYSEC-2026-3848","url":"https://osv.dev/vulnerability/PYSEC-2026-3848","summary":"HTTPX2: Multipart part header injection via unvalidated file Content-Type and custom headers","modified":"2026-09-10T12:15:04.992530880Z","packages":[{"ecosystem":"PyPI","name":"httpx2","purl":"pkg:pypi/httpx2","ranges":["<2.11.0"],"fixed":["2.11.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}