{"items":[{"id":"NVI-00014113","kind":"vulnerability","title":"Tornado: Incomplete fix for CVE-2026-35536: cookie attribute injection re-opened via the legacy case-insensitive `**kwargs` path in `set_cookie`","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-wwv5-g3v4-889x"],"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-4a3827b3cd2ecc32336a7020051bb939"],"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":[],"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-4a3827b3cd2ecc32336a7020051bb939","url":"https://github.com/advisories/GHSA-wwv5-g3v4-889x","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-wwv5-g3v4-889x","publisher":"GitHub Advisory Database","observed_at":"2026-11-02T02:21:50.763Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-4a3827b3cd2ecc32336a7020051bb939"],"technology":"tornado","known_exclusions":[],"conditions_summary":"## Summary\nThe CVE-2026-35536 fix added a validation loop that rejects `[\\x00-\\x20\\x3b\\x7f]`, but only for the\nhardcoded **lowercase** keys `name`/`domain`/`path`/`samesite`. The still-live deprecated `**kwargs` path\nwrites attacker-supplied attribute values straight into the `Morsel` with no validation, and because\n`Morsel.__setitem__` is case-insensitive, a capitalized kwarg (`Domain=`, `Path=`, `SameSite=`, `Max-Age=`)\nroutes to the same reserved attribute while bypassing the loop — re-opening `;`-delimited attribute injection.\n\n```python\nself.set_cookie(\"sid\", \"abc\", Domain=\"evil.com; Secure; SameSite=None\")\n#  -> Set-Cookie: sid=abc; Domain=evil.com; Secure; SameSite=None; Path=/\n# Sanity (the canonical lowercase named arg IS blocked):\nself.set_cookie(\"sid\", \"abc\", domain=\"evil.com; Secure\")   # -> http.cookies.CookieError\n```\n\nThe patch's regression test (`SetCookieForbiddenCharHandler`) only exercises the four named params, never the\n`**kwargs` path, so the gap is not regression-covered.\n\n## Affected code\n- `tornado/web.py` → `RequestHandler.set_cookie`: the validation loop covers only the lowercase named args;\n  the trailing `if kwargs:` loop does `morsel[k] = v` with no ch","public_affected_ranges":[">= 6.5.5, < 6.5.8"]}],"null_published_at":"2026-11-02T10:00:37.208Z","source_updated_at":"2026-09-01T20:17:24.000Z","source_disclosed_at":"2026-09-01T20:17:23.000Z","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":"2026-11-02T02:21:50.763Z"}],"next_cursor":null,"snapshot_revision":"40769"}