CVE-2026-12151

Impact:<br /> The undici WebSocket client enforces maxPayloadSize on the cumulative byte count of fragments in a message but does not enforce a limit on the number of fragments. A malicious WebSocket server can stream many small or empty continuation frames that each pass per-frame and cumulative-size validation, collectively causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service.<br /> <br /> Affected applications are those using the undici WebSocket client (new WebSocket(...)) or the WebSocketStream API that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint.<br /> <br /> All releases starting at undici 6.17.0 are affected.<br /> <br /> Patches: Upgrade to undici &gt;= 6.26.0, &gt;= 7.28.0, or &gt;= 8.5.0. Workarounds:<br /> No workaround is available. The fix must be applied through an upgrade.