A flaw in Node.js TLS error handling allows remote attackers to crash or exhaust resources of a TLS server when `pskCallback` or `ALPNCallback` are in use. Synchronous exceptions thrown during these callbacks bypass standard TLS error handling paths (tlsClientError and error), causing either immediate process termination or silent file descriptor leaks that eventually lead to denial of service. Because these callbacks process attacker-controlled input during the TLS handshake, a remote client can repeatedly trigger the issue. This vulnerability affects TLS servers using PSK or ALPN callbacks across Node.js versions where these callbacks throw without being safely wrapped.

An attacker can make the Node.js HTTP/2 server completely unavailable by sending a small amount of HTTP/2 frames packets with a few HTTP/2 frames inside. It is possible to leave some data in nghttp2 memory after reset when headers with HTTP/2 CONTINUATION frame are sent to the server and then a TCP connection is abruptly closed by the client triggering the Http2Session destructor while header frames are still being processed (and stored in memory) causing a race condition.

Maliciously crafted export names in an imported WebAssembly module can inject JavaScript code. The injected code may be able to access data and functions that the WebAssembly module itself does not have access to, similar to as if the WebAssembly module was a JavaScript module. This vulnerability affects users of any active release line of Node.js. The vulnerable feature is only available if Node.js is started with the `--experimental-wasm-modules` command line option.

Versions of the package semver before 7.5.2 are vulnerable to Regular Expression Denial of Service (ReDoS) via the function new Range, when untrusted user data is provided as a range.