CVE-2026-40347

· NIST NVD ↗

Python-Multipart is a streaming multipart parser for Python. Versions prior to 0.0.26 have a denial of service vulnerability when parsing crafted `multipart/form-data` requests with large preamble or epilogue sections. Upgrade to version 0.0.26 or later, which skips ahead to the next boundary candidate when processing leading CR/LF data and immediately discards epilogue data after the closing boundary.

MEDIUM
CVSS severity
5.3
CVSS base score
2026-04-18
Published

CWE codes

CWE-400CWE-834

Affected products

fastapiexpert:python-multipart

Sources