{"items":[{"id":"NVI-00018534","kind":"vulnerability","title":"tornado AsyncHTTPClient accumulates decompressed chunks without size limit (gzip bomb)","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-mgf9-4vpg-hj56","CVE-2026-49855"],"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-381b6d0a0c32973724eac2ded2f1c0b9"],"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":"2026-06-15T20:20:20.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-381b6d0a0c32973724eac2ded2f1c0b9"}],"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-381b6d0a0c32973724eac2ded2f1c0b9","url":"https://github.com/advisories/GHSA-mgf9-4vpg-hj56","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-mgf9-4vpg-hj56","publisher":"GitHub Advisory Database","observed_at":"2026-11-06T07:20:20.042Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-381b6d0a0c32973724eac2ded2f1c0b9"],"technology":"tornado","known_exclusions":[],"conditions_summary":"Tornado's gzip decompression routines work in limited-size chunks, but have no overall limit for the total size of decompressed chunks that they will accumulate (There has always been a limit for the total *compressed* size). This allows a malicious server to consume effectively unlimited amounts of memory if it is accessed via SimpleAsyncHTTPClient in its default configuration. `HTTPServer` is not affected in its default configuration, but it is if `decompress_request=True` is set.\n\nThis bug is fixed in Tornado 6.5.6. `max_body_size` is now checked both for the compressed and cumulative decompressed size of the response.\n\nPrior to upgrading, this issue can be mitigated by setting `decompress_response=False` or using `CurlAsyncHTTPClient`.","public_affected_ranges":["< 6.5.6"]}],"null_published_at":"2026-11-07T07:07:39.849Z","source_updated_at":"2026-06-15T20:20:20.000Z","source_disclosed_at":"2026-06-15T20:19:28.000Z","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":"2026-11-06T07:20:20.042Z"}],"next_cursor":null,"snapshot_revision":"42594"}