python-multipart has a Denial of service (DoS) via deformation `multipart/form-data` boundary
En bref
Sévérité
HIGH 7.5
EPSS
EPSS 0.64 % · centile 50 (2026-10-28)
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
GitHub_M
Statut NVD
Deferred
Description
python-multipart is a streaming multipart parser for Python. When parsing form data, python-multipart skips line breaks (CR \r or LF \n) in front of the first boundary and any tailing bytes after the last boundary. This happens one byte at a time and emits a log event each time, which may cause excessive logging for certain inputs. An attacker could abuse this by sending a malicious request with lots of data before the first or after the last boundary, causing high CPU load and stalling the processing thread for a significant amount of time. In case of ASGI application, this could stall the event loop and prevent other requests from being processed, resulting in a denial of service (DoS). This vulnerability is fixed in 0.0.18.
