undici WebSocket client vulnerable to denial of service via cumulative fragment bypass

Impact The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, causing...

CVE-2026-9675

The CVE-2026-9675 issue affects the undici WebSocket client (new WebSocket(...)) where per-frame maxPayloadSize is enforced but the cumulative size of fragmented, uncompressed messages is not. A attacker-controlled WebSocket endpoint can stream many small fragments that pass per-frame validation ...