GHSA-MPF4-983Q-P7J4 Tornado: Urlencoded body parsing omits max_num_fields, so one request can stall the event loop

Summary Tornado parses application/x-www-form-urlencoded bodies with urllib.parse.parseqs and does not pass maxnumfields. A body made almost entirely of separators produces tens of millions of fields, and the parse happens on the event loop before the handler runs, so a single request stalls the...

Tornado: Urlencoded body parsing omits max_num_fields, so one request can stall the event loop

Summary Tornado parses application/x-www-form-urlencoded bodies with urllib.parse.parseqs and does not pass maxnumfields. A body made almost entirely of separators produces tens of millions of fields, and the parse happens on the event loop before the handler runs, so a single request stalls the...

DEBIAN-CVE-2026-82397

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.8, Tornado parses application/x-www-form-urlencoded request bodies with urllib.parse.parseqs in tornado/escape.py without passing maxnumfields. RequestHandler.execute in tornado/web.py parses the body before handl...

CVE-2026-82397

Tornado (Python web framework / async networking library), prior to 6.5.8 , parses application/x-www-form-urlencoded request bodies via urllib.parse.parse_qs in tornado/escape.py without passing max_num_fields. Because RequestHandler._execute parses the body before handler dispatch, an unauthenti...