A reachable assertion vulnerability in Node.js HTTP/2 session teardown allows any unauthenticated client to abort the server process. This occurs because an Http2Stream holding nghttp2-allocated header buffers can outlive its session, causing a failed assertion during session destruction. The issue affects Node.js versions 26.x (since 26.9.0) and 24.x (since 24.22.0) and is a variant of a previously fixed vulnerability (CVE-2024-27983).