A vulnerability in the Node.js zlib streaming API allows an uncatchable exception to crash a process when a peer disconnects during compression. This occurs because zlib.params() queues a flush operation that completes in a callback, which asserts on a native handle that may no longer exist if the stream is destroyed, causing an internal assertion error that terminates the process. The issue affects Node.js versions 22.x, 24.x, and 26.x and requires the application to call deflate.params() while streaming to a peer, which is uncommon.