PYSEC-2026-249

Starlette is a lightweight ASGI framework/toolkit. From 0.4.1 until 1.3.1, request.form accepts maxfields and maxpartsize to bound resource consumption while parsing form data. These limits are enforced for multipart/form-data, but silently ignored for application/x-www-form-urlencoded. An...

CVE-2026-54283

Starlette is a lightweight ASGI framework/toolkit. From 0.4.1 until 1.3.1, request.form accepts maxfields and maxpartsize to bound resource consumption while parsing form data. These limits are enforced for multipart/form-data, but silently ignored for application/x-www-form-urlencoded. An...

python-multipart: Semicolon treated as querystring field separator enables parameter smuggling

Summary QuerystringParser treated ; as a field separator in application/x-www-form-urlencoded bodies, in addition to &. The WHATWG URL standard, modern browsers, and Python's urllib.parse since the CVE-2021-23336 fix treat only & as a separator. This creates a parser differential: the same bytes...