undici WebSocket client vulnerable to Denial of Service via unbounded automatic PONG buffering

影響: npm:undici >= 5.15.0, < 6.29.1 → 6.29.1, npm:undici >= 7.0.0, < 7.30.1 → 7.30.1, npm:undici >= 8.0.0, < 8.12.2 → 8.12.2

undici's WebSocket client (including Node.js's bundled globalThis.WebSocket) can be driven to exhaust process memory by a malicious or compromised WebSocket server. For every PING frame received, the receiver automatically writes a PONG response to the socket and ignores the false return value from socket.write(), which is a backpressure signal, so a server that streams small PING frames while never reading the client's PONGs makes the outbound write queue and heap grow without bound until the…

Read on GitHub Advisory Database

On 10/28/2026, 04:02 AM, GitHub Advisory Database published "undici WebSocket client vulnerable to Denial of Service via unbounded automatic PONG buffering" (type: Advisory). Severity is "Medium" (medium). Related technologies: JavaScript / Node.js. CVE: CVE-2026-109932.