Description
daphne before 4.2.2 did not pass maxFramePayloadSize or maxMessagePayloadSize to Autobahn's WebSocketServerFactory. Because Autobahn defaults both values to 0 (unlimited), an unauthenticated remote attacker could send arbitrarily large WebSocket messages or frames, causing excessive memory consumption and a denial of service.
Problem types
CWE-770 (Allocation of Resources Without Limits or Throttling)
Product status
4.2.0 (python)
4.2.2 (python)
Timeline
| 2026-04-18: | Initial report received. |
| 2026-05-06: | Vulnerability confirmed. |
Credits
ParkHyunWoo
Carlton Gibson
References
github.com/django/daphne/blob/main/CHANGELOG.txt