PYSEC-2026-2670 multipart vulnerable to ReDoS in `parse_options_header()`

Summary The parseoptionsheader function in multipart.py uses a regular expression with an ambiguous alternation, which can cause exponential backtracking ReDoS when parsing maliciously crafted HTTP or multipart segment headers. This can be abused for denial of service DoS attacks against web...

Regular Expression Denial of Service (ReDoS)

Overview multipart is a Parser for multipart/form-data Affected versions of this package are vulnerable to Regular Expression Denial of Service ReDoS in the parseoptionsheader function due to the use of a regular expression with ambiguous alternation. An attacker can cause significant resource...