{"items":[{"id":"NVI-00013154","kind":"vulnerability","title":"Tornado: Unbounded query-string argument count allows event-loop-stalling DoS","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-3hv7-mjh2-fv65"],"plain_summary":"GitHub lists this reviewed advisory for tornado. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-78780984128094ad6d8c394c5a78e351"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-09-30T23:49:26.000Z","value":"5.3 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-78780984128094ad6d8c394c5a78e351"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-78780984128094ad6d8c394c5a78e351","url":"https://github.com/advisories/GHSA-3hv7-mjh2-fv65","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-3hv7-mjh2-fv65","publisher":"GitHub Advisory Database","observed_at":"2026-11-01T07:22:52.960Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-78780984128094ad6d8c394c5a78e351"],"technology":"tornado","known_exclusions":[],"conditions_summary":"## Summary\n\n`HTTPServerRequest.__init__` in `tornado/httputil.py` parses the URL query string via\n`parse_qs_bytes()` with no field-count limit — while the sibling POST-body parsing path\n(`parse_body_arguments`) received a `max_num_fields=1000` cap added earlier in this exact\nsame release (v6.5.8, commit `8d6363ed`), explicitly to bound parsing cost for the identical\nunderlying primitive. This leaves the query-string path with the resource-exhaustion exposure\nthe body-path fix was meant to close.\n\n**File**: `tornado/httputil.py`, line 553 (`HTTPServerRequest.__init__`)\n\n### Root Cause\n\n```python\n# tornado/httputil.py:553 (before fix)\nself.arguments = parse_qs_bytes(self.query, keep_blank_values=True)\n```\n\nCompare with the POST-body path fixed one commit earlier in the same release:\n\n```python\n# tornado/httputil.py:1038-1041\nuri_arguments = parse_qs_bytes(\n    body,\n    keep_blank_values=True,\n    max_num_fields=config.urlencoded.max_arguments,  # default 1000\n)\n```\n\nBoth call sites funnel through the same `tornado.escape.parse_qs_bytes` (a thin wrapper over\n`urllib.parse.parse_qs`), which is exactly why `max_num_fields` was added to\n`urllib.parse.parse_qsl` upstream — to let framewo","public_affected_ranges":["<= 6.5.8"]}],"null_published_at":"2026-11-01T07:29:12.926Z","source_updated_at":"2026-09-30T23:49:26.000Z","source_disclosed_at":"2026-09-30T23:49:25.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-01T07:22:52.960Z"}],"next_cursor":null,"snapshot_revision":"42594"}