A malformed HTTP/2 HEADERS frame with oversized, invalid HPACK data can cause Node.js to crash by triggering an unhandled TLSSocket error ECONNRESET. Instead of safely closing the connection, the process crashes, enabling a remote denial of service. This primarily affects applications that do not attach explicit error handlers to secure sockets, for example:

server.on('secureConnection', socket => {
  socket.on('error', err => {
    console.log(err)
  })
})

References

• https://nvd.nist.gov/vuln/detail/CVE-2025-59465
• https://nodejs.org/en/blog/vulnerability/december-2025-security-releases